Mauveine, the first commercial aniline dye[edit]
Main article: Mauveine
The
synthetic dye mauve was first so named in 1859. Chemist William Henry
Perkin, then eighteen, was attempting in 1856 to synthesize quinine,
which was used to treat malaria.[8] An unexpected residue caught his
eye, which turned out to be the first aniline dye. Perkin originally
named the dye Tyrian purple after the historical dye, but the product
was renamed mauve after it was marketed in 1859.[9][10] It is now
usually called Perkin's mauve, mauveine, or aniline purple.
Earlier
references to a mauve dye in 1856–1858 referred to a color produced
using the semi-synthetic dye murexide or a mixture of natural dyes.[11]
Perkin was so successful in marketing his discovery to the dye industry
that his biography by Simon Garfield is simply entitled Mauve.[12]
However, as it faded easily, the success of mauve dye was short-lived
and it was replaced by other synthetic dyes by 1873.[13] As the memory
of the original dye soon receded, the contemporary understanding of
mauve is as a lighter, less-saturated color than it was originally
known.[14]
The 1890s are sometimes referred to
in retrospect as the "Mauve Decade" because of the characteristic
popularity of the subtle color among progressive artistic types, both in
Europe and the US....
Variations[edit]
Rich mauve[edit]
Mauve (Crayola)
About these coordinates Color coordinates
Hex triplet #E285FF
sRGBB (r, g, b) (226, 133, 255)
CMYKH (c, m, y, k) (11, 48, 0, 0)
HSV (h, s, v) (286°, 48%, 100[16]%)
Source Crayola
ISCC–NBS descriptor Vivid purple
B: Normalized to [0–255] (byte)
H: Normalized to [0–100] (hundred)
The color displayed at right is the rich tone of mauve called mauve by Crayola.
French mauve (deep mauve)[edit]
Mauve (Pourpre)
About these coordinates Color coordinates
Hex triplet #D473D4
sRGBB (r, g, b) (212, 115, 212)
CMYKH (c, m, y, k) (0, 46, 0, 17)
HSV (h, s, v) (300°, 46%, 83[17]%)
Source Pourpre
ISCC–NBS descriptor Vivid purple
B: Normalized to [0–255] (byte)
H: Normalized to [0–100] (hundred)
The
color displayed at right is the deep tone of mauve that is called mauve
by Pourpre.com, a color list widely popular in France.
Opera mauve[edit]
Opera mauve
About these coordinates Color coordinates
Hex triplet #B784A7
sRGBB (r, g, b) (183, 132, 167)
CMYKH (c, m, y, k) (12, 27, 0, 2)
HSV (h, s, v) (276°, 20%, 62%)
Source ISCC-NBS
ISCC–NBS descriptor Light reddish purple
B: Normalized to [0–255] (byte)
H: Normalized to [0–100] (hundred)
The color displayed at right is opera mauve.
The first recorded use of opera mauve as a color name in English was in 1927.[18]
Mauve taupe[edit]
Mauve taupe
About these coordinates Color coordinates
Hex triplet #915F6D
sRGBB (r, g, b) (145, 95, 109)
CMYKH (c, m, y, k) (0, 34, 25, 43)
HSV (h, s, v) (285°, 37%, 54%)
Source ISCC-NBS
ISCC–NBS descriptor Grayish purplish red
B: Normalized to [0–255] (byte)
H: Normalized to [0–100] (hundred)
Main article: Taupe
The color displayed at right is mauve taupe.
The first recorded use of mauve taupe as a color name in English was in 1925.[19]
Old mauve[edit]
Old mauve
About these coordinates Color coordinates
Hex triplet #673147
sRGBB (r, g, b) (103, 49, 71)
CMYKH (c, m, y, k) (0, 52, 31, 60)
HSV (h, s, v) (336°, 52%, 40[20]%)
Source ISCC-NBS
ISCC–NBS descriptor Dark purplish red
B: Normalized to [0–255] (byte)
H: Normalized to [0–100] (hundred)
The color displayed at right is old mauve.
The first recorded use of old mauve as a color name in English was in 1925." (wikipedia.org)
"Made in Germany is a merchandise mark indicating that a product has been manufactured in Germany....
The
label was originally introduced in Britain by the Merchandise Marks Act
1887,[1] to mark foreign produce more obviously, as foreign
manufactures had been falsely marking inferior goods with the marks of
renowned British manufacturing companies and importing them into the
United Kingdom. Most of these were found to be originating from Germany,
whose government had introduced a protectionist policy to legally
prohibit the import of goods in order to build up domestic industry
(Merchandise Marks Act - Oxford University Press).[2]
According
to Professor Asaf Zussman, Department of Economics, Hebrew University
in "The Rise of German Protectionism in the 1870s: A Macroeconomic
Perspective∗", the "Rye and Iron" tariffs introduced by Bismarck’s
Germany in 1879 caused a major reduction of imports in order to protect
Germany's industries. As a response, the Free-trade Liberal government
in the UK introduced the Merchandise Marks act to allow consumers to be
able to choose whether or not they would continue to purchase goods from
protectionist economies.
Germany successfully leveraged the Made in Germany tag as a brand synonymous of product reliability and quality.[3][4][5][6][7]
"Made
in Germany" is not controlled by a central regulatory body. However,
its status has been defined by several court rulings in
Germany.[citation needed] In 1973, the Bundesgerichtshof made a ruling
that Made in Germany does not enable people to properly distinguish
between the two Germanys of the time, so Made in West Germany and Made
in GDR became popular. In 1995, the Oberlandesgericht Stuttgart ruled
that the term Made in Germany is misleading according to Germany's Fair
Trades Act when the largest part is not German raw materials or German
craftsmanship." (wikipedia.org)
"Pottery
is the process of forming vessels and other objects with clay and other
ceramic materials, which are fired at high temperatures to give them a
hard, durable form. Major types include earthenware, stoneware and
porcelain. The place where such wares are made by a potter is also
called a pottery (plural "potteries"). The definition of pottery used by
the American Society for Testing and Materials (ASTM), is "all fired
ceramic wares that contain clay when formed, except technical,
structural, and refractory products."[1] In archaeology, especially of
ancient and prehistoric periods, "pottery" often means vessels only, and
figures etc. of the same material are called "terracottas". Clay as a
part of the materials used is required by some definitions of pottery,
but this is dubious.
Pottery from Székely Land, Romania, on sale in Budapest.
Pottery
is one of the oldest human inventions, originating before the Neolithic
period, with ceramic objects like the Gravettian culture Venus of Dolní
Věstonice figurine discovered in the Czech Republic dating back to
29,000–25,000 BC,[2] and pottery vessels that were discovered in
Jiangxi, China, which date back to 18,000 BC. Early Neolithic and
pre-Neolithic pottery artifacts have been found, in Jōmon Japan (10,500
BC),[3] the Russian Far East (14,000 BC),[4] Sub-Saharan Africa (9,400
BC),[5] South America (9,000s-7,000s BC),[6] and the Middle East
(7,000s-6,000s BC).
Pottery is made by forming a
ceramic (often clay) body into objects of a desired shape and heating
them to high temperatures (600-1600 °C) in a bonfire, pit or kiln and
induces reactions that lead to permanent changes including increasing
the strength and rigidity of the object. Much pottery is purely
utilitarian, but much can also be regarded as ceramic art. A clay body
can be decorated before or after firing.
Clay Pot (Ghaila) in Nepal
The pottery market in Boubon, Niger.
Clay-based
pottery can be divided into three main groups: earthenware, stoneware
and porcelain. These require increasingly more specific clay material,
and increasingly higher firing temperatures. All three are made in
glazed and unglazed varieties, for different purposes. All may also be
decorated by various techniques. In many examples the group a piece
belongs to is immediately visually apparent, but this is not always the
case. The fritware of the Islamic world does not use clay, so
technically falls outside these groups. Historic pottery of all these
types is often grouped as either "fine" wares, relatively expensive and
well-made, and following the aesthetic taste of the culture concerned,
or alternatively "coarse", "popular" "folk" or "village" wares, mostly
undecorated, or simply so, and often less well-made....
Main types[edit]
Earthenware pottery from the Neolithic Longshan culture, China, 3rd millennium BC
Earthenware[edit]
Main article: Earthenware
All
the earliest forms of pottery were made from clays that were fired at
low temperatures, initially in pit-fires or in open bonfires. They were
hand formed and undecorated. Earthenware can be fired as low as 600 °C,
and is normally fired below 1200 °C.[7] Because unglazed biscuit
earthenware is porous, it has limited utility for the storage of liquids
or as tableware. However, earthenware has had a continuous history from
the Neolithic period to today. It can be made from a wide variety of
clays, some of which fire to a buff, brown or black colour, with iron in
the constituent minerals resulting in a reddish-brown. Reddish coloured
varieties are called terracotta, especially when unglazed or used for
sculpture. The development of ceramic glaze made impermeable pottery
possible, improving the popularity and practicality of pottery vessels.
The addition of decoration has evolved throughout its history.
Stoneware[edit]
15th-century Japanese stoneware storage jar, with partial ash glaze
Main article: Stoneware
Stoneware
is pottery that has been fired in a kiln at a relatively high
temperature, from about 1,100 °C to 1,200 °C, and is stronger and
non-porous to liquids.[8] The Chinese, who developed stoneware very
early on, classify this together with porcelain as high-fired wares. In
contrast, stoneware could only be produced in Europe from the late
Middle Ages, as European kilns were less efficient, and the right type
of clay less common. It remained a speciality of Germany until the
Renaissance.[9]
Stoneware is very tough and
practical, and much of it has always been utilitarian, for the kitchen
or storage rather than the table. But "fine" stoneware has been
important in China, Japan and the West, and continues to be made. Many
utilitarian types have also come to be appreciated as art.
Porcelain[edit]
Chantilly porcelain teapot, c. 1730, with chinoiserie decoration in overglaze enamels
Main article: Porcelain
Porcelain
is made by heating materials, generally including kaolin, in a kiln to
temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F). This is
higher than used for the other types, and achieving these temperatures
was a long struggle, as well as realizing what materials were needed.
The toughness, strength and translucence of porcelain, relative to other
types of pottery, arises mainly from vitrification and the formation of
the mineral mullite within the body at these high temperatures.
Although
porcelain was first made in China, the Chinese traditionally do not
recognise it as a distinct category, grouping it with stoneware as
"high-fired" ware, opposed to "low-fired" earthenware. This confuses the
issue of when it was first made. A degree of translucency and whiteness
was achieved by the Tang dynasty (AD 618–906), and considerable
quantities were being exported. The modern level of whiteness was not
reached until much later, in the 14th century. Porcelain was also made
in Korea and in Japan from the end of the 16th century, after suitable
kaolin was located in those countries. It was not made effectively
outside East Asia until the 18th century.[10]
Production stages[edit]
Before
being shaped, clay must be prepared. Kneading helps to ensure an even
moisture content throughout the body. Air trapped within the clay body
needs to be removed. This is called de-airing and can be accomplished
either by a machine called a vacuum pug or manually by wedging. Wedging
can also help produce an even moisture content. Once a clay body has
been kneaded and de-aired or wedged, it is shaped by a variety of
techniques. After it has been shaped, it is dried and then fired.
Greenware
refers to unfired objects. At sufficient moisture content, bodies at
this stage are in their most plastic form (as they are soft and
malleable, and hence can be easily deformed by handling).
Leather-hard
refers to a clay body that has been dried partially. At this stage the
clay object has approximately 15% moisture content. Clay bodies at this
stage are very firm and only slightly pliable. Trimming and handle
attachment often occurs at the leather-hard state.
Bone-dry
refers to clay bodies when they reach a moisture content at or near 0%.
At that moisture content, the item is ready to be fired.
Biscuit
(or bisque)[11][12] refers to the clay after the object is shaped to
the desired form and fired in the kiln for the first time, known as
"bisque fired" or "biscuit fired". This firing changes the clay body in
several ways. Mineral components of the clay body will undergo chemical
and physical changes that will change the material.
Glaze
fired is the final stage of some pottery making, or glost fired.[13] A
glaze may be applied to the bisque form and the object can be decorated
in several ways. After this the object is "glazed fired", which causes
the glaze material to melt, then adhere to the object. Depending on the
temperature schedule the glaze firing may also further mature the body
as chemical and physical changes continue.
Clay bodies and mineral contents[edit]
Preparation of clay for pottery in India
Body
is a term for the main pottery form of a piece, underneath any glaze or
decoration. The main ingredient of the body is clay. There are several
materials that are referred to as clay. The properties which make them
different include: Plasticity, the malleability of the body; the extent
to which they will absorb water after firing; and shrinkage, the extent
of reduction in size of a body as water is removed. Different clay
bodies also differ in the way in which they respond when fired in the
kiln. A clay body can be decorated before or after firing. Prior to some
shaping processes, clay must be prepared. Each of these different clays
is composed of different types and amounts of minerals that determine
the characteristics of resulting pottery. There can be regional
variations in the properties of raw materials used for the production of
pottery, and these can lead to wares that are unique in character to a
locality. It is common for clays and other materials to be mixed to
produce clay bodies suited to specific purposes. A common component of
clay bodies is the mineral kaolinite. Other minerals in the clay, such
as feldspar, act as fluxes which lower the vitrification temperature of
bodies. Following is a list of different types of clay used for
pottery.[14]
Kaolin, is sometimes referred to as china clay because it was first used in China. Used for porcelain.
Ball
clay An extremely plastic, fine grained sedimentary clay, which may
contain some organic matter. Small amounts can be added to porcelain
bodies to increase plasticity.
Fire clay A clay having a
slightly lower percentage of fluxes than kaolin, but usually quite
plastic. It is highly heat resistant form of clay which can be combined
with other clays to increase the firing temperature and may be used as
an ingredient to make stoneware type bodies.
Stoneware clay
Suitable for creating stoneware. Has many of the characteristics between
fire clay and ball clay, having finer grain, like ball clay but is more
heat resistant like fire clays.
Common red clay and shale
clay have vegetable and ferric oxide impurities which make them useful
for bricks, but are generally unsatisfactory for pottery except under
special conditions of a particular deposit.[15]
Bentonite An extremely plastic clay which can be added in small quantities to short clay to increase the plasticity.
Methods of shaping[edit]
File:PotteryShaping.ogv
A potter shapes a piece of pottery on an electric-powered potter's wheel
Pottery can be shaped by a range of methods that include:
Hand-building.
This is the earliest forming method. Wares can be constructed by hand
from coils of clay, combining flat slabs of clay, or pinching solid
balls of clay or some combination of these. Parts of hand-built vessels
are often joined together with the aid of slip, an aqueous suspension of
clay body and water. A clay body can be decorated before or after
firing. Prior to some shaping processes, clay must be prepared, such as
tablewares, although some studio potters find hand-building more
conducive to create one-of-a-kind works of art.
Classic potter's kick wheel in Erfurt, Germany
The
potter's wheel. In a process called "throwing" (coming from the Old
English word thrownاا which means to twist or turn,[16]) a ball of clay
is placed in the center of a turntable, called the wheel-head, which the
potter rotates with a stick, with foot power or with a variable-speed
electric motor.
During the process of throwing, the wheel
rotates while the solid ball of soft clay is pressed, squeezed and
pulled gently upwards and outwards into a hollow shape. The first step
of pressing the rough ball of clay downward and inward into perfect
rotational symmetry is called centring the clay—a most important skill
to master before the next steps: opening (making a centred hollow into
the solid ball of clay), flooring (making the flat or rounded bottom
inside the pot), throwing or pulling (drawing up and shaping the walls
to an even thickness), and trimming or turning (removing excess clay to
refine the shape or to create a foot).
Considerable skill and
experience are required to throw pots of an acceptable standard and,
while the ware may have high artistic merit, the reproducibility of the
method is poor.[13] Because of its inherent limitations, throwing can
only be used to create wares with radial symmetry on a vertical axis.
These can then be altered by impressing, bulging, carving, fluting, and
incising. In addition to the potter's hands these techniques can use
tools, including paddles, anvils & ribs, and those specifically for
cutting or piercing such as knives, fluting tools, needle tools and
wires. Thrown pieces can be further modified by the attachment of
handles, lids, feet and spouts.
Granulate pressing: As the
name suggests, this is the operation of shaping pottery by pressing clay
in a semi-dry and granulated condition in a mould. The clay is pressed
into the mould by a porous die through which water is pumped at high
pressure. The granulated clay is prepared by spray-drying to produce a
fine and free-flowing material having a moisture content of between
about 5 and 6 per cent. Granulate pressing, also known as dust pressing,
is widely used in the manufacture of ceramic tiles and, increasingly,
of plates.
Injection moulding: This is a shape-forming process
adapted for the tableware industry from the method long established for
the forming of thermoplastic and some metal components.[17] It has been
called Porcelain Injection Moulding, or PIM.[18] Suited to the mass
production of complex-shaped articles, one significant advantage of the
technique is that it allows the production of a cup, including the
handle, in a single process, and thereby eliminates the handle-fixing
operation and produces a stronger bond between cup and handle.[19] The
feed to the mould die is a mix of approximately 50 to 60 per cent
unfired body in powder form, together with 40 to 50 per cent organic
additives composed of binders, lubricants and plasticisers.[18] The
technique is not as widely used as other shaping methods.[20]
Jiggering
and jolleying: These operations are carried out on the potter's wheel
and allow the time taken to bring wares to a standardized form to be
reduced. Jiggering is the operation of bringing a shaped tool into
contact with the plastic clay of a piece under construction, the piece
itself being set on a rotating plaster mould on the wheel. The jigger
tool shapes one face while the mould shapes the other. Jiggering is used
only in the production of flat wares, such as plates, but a similar
operation, jolleying, is used in the production of hollow-wares such as
cups. Jiggering and jolleying have been used in the production of
pottery since at least the 18th century. In large-scale factory
production, jiggering and jolleying are usually automated, which allows
the operations to be carried out by semi-skilled labour.
Two moulds for terracotta, with modern casts, from ancient Athens, 5–4th centuries BC
Roller-head
machine: This machine is for shaping wares on a rotating mould, as in
jiggering and jolleying, but with a rotary shaping tool replacing the
fixed profile. The rotary shaping tool is a shallow cone having the same
diameter as the ware being formed and shaped to the desired form of the
back of the article being made. Wares may in this way be shaped, using
relatively unskilled labour, in one operation at a rate of about twelve
pieces per minute, though this varies with the size of the articles
being produced. Developed in the UK just after World War II by the
company Service Engineers, roller-heads were quickly adopted by
manufacturers around the world; they remain the dominant method for
producing flatware.[21]
Pressure casting: Specially developed
polymeric materials allow a mould to be subject to application external
pressures of up to 4.0 MPa – so much higher than slip casting in plaster
moulds where the capillary forces correspond to a pressure of around
0.1–0.2 MPa. The high pressure leads to much faster casting rates and,
hence, faster production cycles. Furthermore, the application of high
pressure air through the polymeric moulds upon demoulding the cast means
a new casting cycle can be started immediately in the same mould,
unlike plaster moulds which require lengthy drying times. The polymeric
materials have much greater durability than plaster and, therefore, it
is possible to achieve shaped products with better dimensional
tolerances and much longer mould life. Pressure casting was developed in
the 1970s for the production of sanitaryware although, more recently,
it has been applied to tableware.[22][23][24][25]
RAM
pressing: This is used to shape ware by pressing a bat of prepared clay
body into a required shape between two porous moulding plates. After
pressing, compressed air is blown through the porous mould plates to
release the shaped wares.
Slipcasting: This is suited to the
making of shapes that cannot be formed by other methods. A liquid slip,
made by mixing clay body with water, is poured into a highly absorbent
plaster mould. Water from the slip is absorbed into the mould leaving a
layer of clay body covering its internal surfaces and taking its
internal shape. Excess slip is poured out of the mould, which is then
split open and the moulded object removed. Slipcasting is widely used in
the production of sanitaryware and is also used for making other
complex shaped ware such as teapots and figurines.
3D
printing: This is the latest advance in forming ceramic objects. There
are two methods. One involves the layered deposition of soft clay
similar to FDM printing the other and powder binding techniques where
dry clay powder is fused together layer upon layer with a liquid.
Decorating and glazing[edit]
Contemporary pottery from the State of Hidalgo, Mexico
Italian red earthenware vase covered with a mottled pale blue glaze
Pottery may be decorated in many different ways. Some decoration can be done before or after the firing.
Decoration[edit]
Painting
has been used since early prehistoric times, and can be very elaborate.
The painting is often applied to pottery that has been fired once, and
may then be overlaid with a glaze afterwards. Many pigments change
colour when fired, and the painter must allow for this.
Glaze
Perhaps the most common form of decoration, that also serves as
protection to the pottery, by being tougher and keeping liquid from
penetrating the pottery. Glaze may be clear, especially over painting,
or coloured and opaque. There is more detail in the section below.
Carving
Pottery vessels may be decorated by shallow carving of the clay body,
typically with a knife or similar instrument used on the wheel. This is
common in Chinese porcelain of the classic periods.
Burnishing
the surface of pottery wares may be burnished prior to firing by
rubbing with a suitable instrument of wood, steel or stone to produce a
polished finish that survives firing. It is possible to produce very
highly polished wares when fine clays are used or when the polishing is
carried out on wares that have been partially dried and contain little
water, though wares in this condition are extremely fragile and the risk
of breakage is high.
Terra Sigillata is an ancient form of decorating ceramics that was first developed in Ancient Greece.
Additives
can be worked into the clay body prior to forming, to produce desired
effects in the fired wares. Coarse additives such as sand and grog
(fired clay which has been finely ground) are sometimes used to give the
final product a required texture. Contrasting coloured clays and grogs
are sometimes used to produce patterns in the finished wares.
Colourants, usually metal oxides and carbonates, are added singly or in
combination to achieve a desired colour. Combustible particles can be
mixed with the body or pressed into the surface to produce texture.
Lithography,
also called litho, although the alternative names of transfer print or
"decal" are also common. These are used to apply designs to articles.
The litho comprises three layers: the colour, or image, layer which
comprises the decorative design; the cover coat, a clear protective
layer, which may incorporate a low-melting glass; and the backing paper
on which the design is printed by screen printing or lithography. There
are various methods of transferring the design while removing the
backing-paper, some of which are suited to machine application.
Banding
is the application by hand or by machine of a band of colour to the
edge of a plate or cup. Also known as "lining", this operation is often
carried out on a potter's wheel.
Agateware is named after its
resemblance to the quartz mineral agate which has bands or layers of
colour that are blended together, agatewares are made by blending clays
of differing colours together but not mixing them to the extent that
they lose their individual identities. The wares have a distinctive
veined or mottled appearance. The term "agateware" is used to describe
such wares in the United Kingdom; in Japan the term "neriage" is used
and in China, where such things have been made since at least the Tang
Dynasty, they are called "marbled" wares. Great care is required in the
selection of clays to be used for making agatewares as the clays used
must have matching thermal movement characteristics.
An ancient Armenian urn
Engobe:
This is a clay slip, that is used to coat the surface of pottery,
usually before firing. Its purpose is often decorative though it can
also be used to mask undesirable features in the clay to which it is
applied. Engobe slip may be applied by painting or by dipping to provide
a uniform, smooth, coating. Engobe has been used by potters from
pre-historic times until the present day and is sometimes combined with
sgraffito decoration, where a layer of engobe is scratched through to
reveal the colour of the underlying clay. With care it is possible to
apply a second coat of engobe of a different colour to the first and to
incise decoration through the second coat to expose the colour of the
underlying coat. Engobes used in this way often contain substantial
amounts of silica, sometimes approaching the composition of a glaze.
Gold: Decoration with gold is used on some high quality ware. Different methods exist for its application, including:
Best
gold – a suspension of gold powder in essential oils mixed with a flux
and a mercury salt extended. This can be applied by a painting
technique. From the kiln, the decoration is dull and requires burnishing
to reveal the full colour
Acid Gold – a form of gold
decoration developed in the early 1860s at the English factory of
Mintons Ltd, Stoke-on-Trent. The glazed surface is etched with diluted
hydrofluoric acid prior to application of the gold. The process demands
great skill and is used for the decoration only of ware of the highest
class.
Bright Gold – consists of a solution of gold
sulphoresinate together with other metal resonates and a flux. The name
derives from the appearance of the decoration immediately after removal
from the kiln as it requires no burnishing
Mussel Gold – an
old method of gold decoration. It was made by rubbing together gold
leaf, sugar and salt, followed by washing to remove solubles
Glaze[edit]
Main article: Ceramic glaze
Two panels of earthenware tiles painted with polychrome glazes over a white glaze, Iran, first half of the 19th century.
Glaze
is a glassy coating on pottery, the primary purposes of which are
decoration and protection. One important use of glaze is to render
porous pottery vessels impermeable to water and other liquids. Glaze may
be applied by dusting the unfired composition over the ware or by
spraying, dipping, trailing or brushing on a thin slurry composed of the
unfired glaze and water. The colour of a glaze after it has been fired
may be significantly different from before firing. To prevent glazed
wares sticking to kiln furniture during firing, either a small part of
the object being fired (for example, the foot) is left unglazed or,
alternatively, special refractory "spurs" are used as supports. These
are removed and discarded after the firing.
Some specialised glazing techniques include:
Salt-glazing,
where common salt is introduced to the kiln during the firing process.
The high temperatures cause the salt to volatize, depositing it on the
surface of the ware to react with the body to form a sodium
aluminosilicate glaze. In the 17th and 18th centuries, salt-glazing was
used in the manufacture of domestic pottery. Now, except for use by some
studio potters, the process is obsolete. The last large-scale
application before its demise in the face of environmental clean air
restrictions was in the production of salt-glazed sewer-pipes.[26][27]
Ash
glazing – ash from the combustion of plant matter has been used as the
flux component of glazes. The source of the ash was generally the
combustion waste from the fuelling of kilns although the potential of
ash derived from arable crop wastes has been investigated.[28] Ash
glazes are of historical interest in the Far East although there are
reports of small-scale use in other locations such as the Catawba Valley
Pottery in the United States. They are now limited to small numbers of
studio potters who value the unpredictability arising from the variable
nature of the raw material.[29]
Underglaze decoration (in the
manner of many blue and white wares). Underglaze may be applied by brush
strokes, air brush, or by pouring the underglaze into the mould,
covering the inside, creating a swirling effect, then the mould is
filled with slip.
In-glaze decoration
On-glaze decoration
Enamel
Firing[edit]
Pottery firing mound in Kalabougou, Mali. All the earliest pottery was made in firing pits of this sort.
A kiln at a pottery in Bardon Mill, UK
Firing
produces irreversible changes in the body. It is only after firing that
the article or material is pottery. In lower-fired pottery, the changes
include sintering, the fusing together of coarser particles in the body
at their points of contact with each other. In the case of porcelain,
where different materials and higher firing-temperatures are used, the
physical, chemical and mineralogical properties of the constituents in
the body are greatly altered. In all cases, the reason for firing is to
permanently harden the wares and the firing regime must be appropriate
to the materials used to make them. As a rough guide, modern
earthenwares are normally fired at temperatures in the range of about
1,000°C (1,830 °F) to 1,200 °C (2,190 °F); stonewares at between about
1,100 °C (2,010 °F) to 1,300 °C (2,370 °F); and porcelains at between
about 1,200 °C (2,190 °F) to 1,400 °C (2,550 °F). Historically, reaching
high temperatures was a long-lasting challenge, and earthenware can be
fired effectively as low as 600°C, achievable in primitive pit firing.
Firing
pottery can be done using a variety of methods, with a kiln being the
usual firing method. Both the maximum temperature and the duration of
firing influences the final characteristics of the ceramic. Thus, the
maximum temperature within a kiln is often held constant for a period of
time to soak the wares to produce the maturity required in the body of
the wares.
The atmosphere within a kiln during
firing can affect the appearance of the finished wares. An oxidising
atmosphere, produced by allowing an excess of air in the kiln, can cause
the oxidation of clays and glazes. A reducing atmosphere, produced by
limiting the flow of air into the kiln, or burning coal rather than
wood, can strip oxygen from the surface of clays and glazes. This can
affect the appearance of the wares being fired and, for example, some
glazes containing iron-rich minerals fire brown in an oxidising
atmosphere, but green in a reducing atmosphere. The atmosphere within a
kiln can be adjusted to produce complex effects in glaze.
Kilns
may be heated by burning wood, coal and gas, or by electricity. When
used as fuels, coal and wood can introduce smoke, soot and ash into the
kiln which can affect the appearance of unprotected wares. For this
reason, wares fired in wood- or coal-fired kilns are often placed in the
kiln in saggars, ceramic boxes, to protect them. Modern kilns powered
by gas or electricity are cleaner and more easily controlled than older
wood- or coal-fired kilns and often allow shorter firing times to be
used. In a Western adaptation of traditional Japanese Raku ware firing,
wares are removed from the kiln while hot and smothered in ashes, paper
or woodchips which produces a distinctive carbonised appearance. This
technique is also used in Malaysia in creating traditional labu
sayung.[30][31]
In Mali, a firing mound is used
rather than a brick or stone kiln. Unfired pots are first brought to
the place where a mound will be built, customarily by the women and
girls of the village. The mound's foundation is made by placing sticks
on the ground, then:
[...]pots are positioned
on and amid the branches and then grass is piled high to complete the
mound. Although the mound contains the pots of many women, who are
related through their husbands' extended families, each women is
responsible for her own or her immediate family's pots within the mound.
When a mound is completed and the ground around has been swept clean of
residual combustible material, a senior potter lights the fire. A
handful of grass is lit and the woman runs around the circumference of
the mound touching the burning torch to the dried grass. Some mounds are
still being constructed as others are already burning." (wikipedia.org)
"Earthenware
is glazed or unglazed nonvitreous pottery[2] that has normally been
fired below 1200 °C.[3] Porcelain, bone china, and stoneware, all fired
at high enough temperatures to vitrify, are the main other important
types of pottery.
Earthenware comprises "most
building bricks, nearly all European pottery up to the seventeenth
century, most of the wares of Egypt, Persia and the near East; Greek,
Roman and Mediterranean, and some of the Chinese; and the fine
earthenware which forms the greater part of our tableware today"
("today" being 1962).[4] Pit fired earthenware dates back to as early as
29,000–25,000 BC,[5][6] and for millennia, only earthenware pottery was
made, with stoneware gradually developing some 5,000 years ago, but
then apparently disappearing for a few thousand years. Outside East
Asia, porcelain was manufactured only from the 18th century AD, and then
initially as an expensive luxury.
After it is
fired, earthenware is opaque and non-vitreous,[7] soft and capable of
being scratched with a knife.[4] The Combined Nomenclature of the
European Communities describes it as being made of selected clays
sometimes mixed with feldspars and varying amounts of other minerals,
and white or light-colored (i.e., slightly greyish, cream, or ivory)....
Characteristics[edit]
Generally,
earthenware bodies exhibit higher plasticity than most whiteware[8]
bodies and hence are easier to shape by RAM press, roller-head or
potter's wheel than bone china or porcelain.[9][10]
Due
to its porosity, earthenware, with a water absorption of 5-8%, must be
glazed to be watertight.[11] Earthenware has lower mechanical strength
than bone china, porcelain or stoneware, and consequently articles are
commonly made in thicker cross-section, although they are still more
easily chipped.[9]
Darker-colored terracotta
earthenware, typically orange or red due to a comparatively high content
of iron oxide, are widely used for flower pots, tiles and some
decorative and oven ware.[4]
Production[edit]
Terracotta flower pots with terracotta tiles in the background
A general body formulation for contemporary earthenware is 25% kaolin, 25% ball clay, 35% quartz and 15% feldspar.[9][12]
Modern
earthenware may be biscuit (or "bisque")[13][14] fired to temperatures
between 1,000 to 1,150 °C (1,830 to 2,100 °F) and glost-fired[15] (or
"glaze-fired")[4][16] to between 950 to 1,050 °C (1,740 to 1,920 °F),
the usual practice in factories and some studio potteries. Some studio
potters follow the reverse practice, with a low-temperature biscuit
firing and a high-temperature glost firing. The firing schedule will be
determined by the raw materials used and the desired characteristics of
the finished ware.
Historically, such high
temperatures were unattainable in most cultures and periods until modern
times, though Chinese ceramics were far ahead of other cultures in this
respect. Earthenware can be produced at firing temperatures as low as
600 °C (1,112 °F) and many clays will not fire successfully above about
1,000 °C (1,830 °F). Much historical pottery was fired somewhere around
800 °C (1,470 °F), giving a wide margin of error where there was no
precise way of measuring temperature, and very variable conditions
within the kiln.
After firing, most earthenware
bodies will be colored white, buff or red. For red earthenware, the
firing temperature affects the color of the clay body. Lower
temperatures produce a typical red terracotta color; higher temperatures
will make the clay brown or even black. Higher firing temperatures may
cause earthenware to bloat.
Types of earthenware[edit]
Chinese earthenware tomb sculpture.[17] The Walters Art Museum.
Despite
the most highly valued types of pottery often switching to stoneware
and porcelain as these were developed by a particular culture, there are
many artistically important types of earthenware. All Ancient Greek and
Ancient Roman pottery is earthenware, as is the Hispano-Moresque ware
of the late Middle Ages, which developed into tin-glazed pottery or
faience traditions in several parts of Europe, mostly notably the
painted maiolica of the Italian Renaissance, and Dutch Delftware. With a
white glaze, these were able to imitate porcelains both from East Asia
and Europe.
Possibly the most complicated
earthenware ever made was the extremely rare Saint-Porchaire ware of the
mid-16th century, apparently made for the French court.
In
the 18th century, especially in English Staffordshire pottery,
technical improvements enabled very fine wares such as Wedgwood's
creamware, that competed with porcelain with considerable success, as
his huge creamware Frog Service for Catherine the Great showed. The
invention of transfer printing processes made highly decorated wares
cheap enough for far wider sections of the population in Europe.
In
China, sancai glazed wares were lead-glazed earthenware, and as
elsewhere, terracotta remained important for sculpture. The Etruscans
had made large sculptures such as statues in it, where the Romans used
it mainly for figurines and Campana reliefs. Chinese painted or Tang
dynasty tomb figures were earthenware, as were later sculptures such as
the near life-size Yixian glazed pottery luohans. After the ceramic
figurine was revived in European porcelain, earthenware figures
followed, such as the popular English Staffordshire figures.
There are other several types of earthenware, including:
Terracotta: a term used for a rather random group of types of objects, rather than being defined by technique
Redware (America)
Victorian majolica
Lusterware with special iridescent glazes
Raku
Ironstone china, on the border of earthenware and stoneware
Yellowware" (wikipedia.org)
"Purple
is any of a variety of colors with hue between red and blue.[1][2] In
the RGB color model used in computer and television screens, purples are
produced by mixing red and blue light. In the RYB color model
historically used by painters, purples are created with a combination of
red and blue pigments. In the CMYK color model used in printing,
purples are made by combining magenta pigment with either cyan pigment,
black pigment, or both.
Purple has long been associated with
royalty, originally because Tyrian purple dye, made from the mucus
secretion of a species of snail, was extremely expensive in
antiquity.[3] Purple was the color worn by Roman magistrates; it became
the imperial color worn by the rulers of the Byzantine Empire and the
Holy Roman Empire, and later by Roman Catholic bishops. Similarly in
Japan, the color is traditionally associated with the emperor and
aristocracy.[4]
According to contemporary surveys in Europe and
the United States, purple is the color most often associated with
rarity, royalty, magic, mystery and piety.[5][6] When combined with
pink, it is associated with eroticism, femininity, and seduction....
Etymology and definitions
The
modern English word purple comes from the Old English purpul, which
derives from Latin purpura, which, in turn, derives from the Greek
πορφύρα (porphura),[8] the name of the Tyrian purple dye manufactured in
classical antiquity from a mucus secreted by the spiny dye-murex
snail.[1][9] The first recorded use of the word purple dates to the late
900s AD.[1]
Relationship to violet
This CIE chromaticity diagram
highlights the line of purples at its base, running from the violet
corner near the left to the red corner at the right.
Purple is
closely associated with violet. In common usage, both refer to a variety
of colors between blue and red in hue.[10][11][12] Historically, purple
has tended to be used for redder hues and violet for bluer
hues.[10][13][14] In optics, violet is a spectral color: It refers to
the color of any different single wavelength of light on the short
wavelength end of the visible spectrum, between approximately 380 and
450 nanometers,[15] whereas purple is the color of various combinations
of red, blue, and violet light,[16][12] some of which humans perceive as
similar to violet.
In art, history, and fashion
In prehistory and the ancient world: Tyrian purple
Main article: Tyrian purple
Byzantine Emperor Justinian I clad in Tyrian purple, 6th-century mosaic at Basilica of San Vitale
Purple
first appeared in prehistoric art during the Neolithic era. The artists
of Pech Merle cave and other Neolithic sites in France used sticks of
manganese and hematite powder to draw and paint animals and the outlines
of their own hands on the walls of their caves. These works have been
dated to between 16,000 and 25,000 BC.[17]
As early as the 15th
century BC the citizens of Sidon and Tyre, two cities on the coast of
Ancient Phoenicia, (present day Lebanon), were producing purple dye from
a sea snail called the spiny dye-murex.[18] Clothing colored with the
Tyrian dye was mentioned in both the Iliad of Homer and the Aeneid of
Virgil.[18] The deep, rich purple dye made from this snail became known
as Tyrian purple.[19]
The process of making the dye was long,
difficult and expensive. Thousands of the tiny snails had to be found,
their shells cracked, the snail removed. Mountains of empty shells have
been found at the ancient sites of Sidon and Tyre. The snails were left
to soak, then a tiny gland was removed and the juice extracted and put
in a basin, which was placed in the sunlight. There, a remarkable
transformation took place. In the sunlight the juice turned white, then
yellow-green, then green, then violet, then a red which turned darker
and darker. The process had to be stopped at exactly the right time to
obtain the desired color, which could range from a bright crimson to a
dark purple, the color of dried blood. Then either wool, linen or silk
would be dyed. The exact hue varied between crimson and violet, but it
was always rich, bright and lasting.[20]
Tyrian purple became the
color of kings, nobles, priests and magistrates all around the
Mediterranean. It was mentioned in the Old Testament; in the Book of
Exodus, God instructs Moses to have the Israelites bring him an offering
including cloth "of blue, and purple, and scarlet,"[21] to be used in
the curtains of the Tabernacle and the garments of priests. The term
used for purple in the 4th-century Latin Vulgate version of the Bible
passage is purpura or Tyrian purple.[22] In the Iliad of Homer, the belt
of Ajax is purple, and the tails of the horses of Trojan warriors are
dipped in purple. In the Odyssey, the blankets on the wedding bed of
Odysseus are purple. In the poems of Sappho (6th century BC) she
celebrates the skill of the dyers of the Greek kingdom of Lydia who made
purple footwear, and in the play of Aeschylus (525–456 BC), Queen
Clytemnestra welcomes back her husband Agamemnon by decorating the
palace with purple carpets. In 950 BC, King Solomon was reported to have
brought artisans from Tyre to provide purple fabrics to decorate the
Temple of Jerusalem.[23]
Alexander the Great (when giving
imperial audiences as the basileus of the Macedonian Empire), the
basileus of the Seleucid Empire, and the kings of Ptolemaic Egypt all
wore Tyrian purple.
The Roman custom of wearing purple togas may
have come from the Etruscans; an Etruscan tomb painting from the 4th
century BC shows a nobleman wearing a deep purple and embroidered toga.
In
Ancient Rome, the Toga praetexta was an ordinary white toga with a
broad purple stripe on its border. It was worn by freeborn Roman boys
who had not yet come of age,[24] curule magistrates,[25][26] certain
categories of priests,[27] and a few other categories of citizens.
The
Toga picta was solid purple, embroidered with gold. During the Roman
Republic, it was worn by generals in their triumphs, and by the Praetor
Urbanus when he rode in the chariot of the gods into the circus at the
Ludi Apollinares.[28] During the Empire, the toga picta was worn by
magistrates giving public gladiatorial games, and by the consuls, as
well as by the emperor on special occasions.
During the Roman
Republic, when a triumph was held, the general being honored wore an
entirely purple toga bordered in gold, and Roman Senators wore a toga
with a purple stripe. However, during the Roman Empire, purple was more
and more associated exclusively with the emperors and their
officers.[29] Suetonius claims that the early emperor Caligula had the
King of Mauretania murdered for the splendour of his purple cloak, and
that Nero forbade the use of certain purple dyes.[30] In the late empire
the sale of purple cloth became a state monopoly protected by the death
penalty.[31]
Jesus Christ, in the hours leading up to his
crucifixion, was dressed in purple (πορφύρα: porphura) by the Roman
garrison to mock his claim to be 'King of the Jews'.[32]
The
actual color of Tyrian purple seems to have varied from a reddish to a
bluish purple. According to the Roman writer Vitruvius, (1st century
BC), the murex shells coming from northern waters, probably Bolinus
brandaris, produced a more bluish color than those of the south,
probably Hexaplex trunculus. The most valued shades were said to be
those closer to the color of dried blood, as seen in the mosaics of the
robes of the Emperor Justinian in Ravenna. The chemical composition of
the dye from the murex is close to that of the dye from indigo, and
indigo was sometimes used to make a counterfeit Tyrian purple, a crime
which was severely punished. What seems to have mattered about Tyrian
purple was not its color, but its luster, richness, its resistance to
weather and light, and its high price.[33]
In modern times,
Tyrian purple has been recreated, at great expense. When the German
chemist Paul Friedander tried to recreate Tyrian purple in 2008, he
needed twelve thousand mollusks to create 1.4 ounces of dye, enough to
color a handkerchief. In the year 2000, a gram of Tyrian purple made
from ten thousand mollusks according to the original formula cost two
thousand euros.[34][35]
China
Main article: Han purple and Han blue
In
ancient China, purple was obtained not through the Mediterranean
mollusc, but purple gromwell. The dye obtained did not easily adhere to
fabrics, making purple fabrics expensive. Purple became a fashionable
color in the state of Qi (齊, 1046 BC–221 BC) because its ruler developed
a preference for it. As a result, the price of a purple spoke of fabric
was in excess of five times that of a plain spoke. His minister, Guan
Zhong (管仲), eventually convinced him to relinquish this preference.
China was the first culture to develop a synthetic purple color.[36]
Old
hypothesis suggested links between Chinese purple and blue with
Egyptian blue, however, molecular structure analysis and evidences such
as the absence of lead in Egyptian blue and the lack of examples of
Egyptian blue in China, argued against the early hypothesis.[37][38] The
use of quartz, barium, and lead components in ancient Chinese glass and
Han purple and Han blue has been used to suggest a connection between
glassmaking and the manufacture of pigments,[39] and to prove for the
independent Chinese invention.[37] Taoist alchemists may have developed
Han purple from their knowledge of glassmaking.[37]
The lead is used by pigment maker to lower the melting point of the barium in Han Purple.[40]
Purple
was regarded as a secondary color in ancient China. In classical times,
secondary colors were not as highly prized as the five primary colors
of the Chinese spectrum, and purple was used to allude to impropriety,
compared to crimson, which was deemed a primary color and thus
symbolized legitimacy. Nevertheless, by the 6th Century, purple was
ranked above crimson. Several changes to the ranks of colors occurred
after that time....
Purple in the Byzantine Empire and Carolingian Europe
Through
the early Christian era, the rulers of the Byzantine Empire continued
the use of purple as the imperial color, for diplomatic gifts, and even
for imperial documents and the pages of the Bible. Gospel manuscripts
were written in gold lettering on parchment that was colored Tyrian
purple.[41] Empresses gave birth in the Purple Chamber, and the emperors
born there were known as "born to the purple," to separate them from
emperors who won or seized the title through political intrigue or
military force. Bishops of the Byzantine church wore white robes with
stripes of purple, while government officials wore squares of purple
fabric to show their rank.
In western Europe, the Emperor
Charlemagne was crowned in 800 wearing a mantle of Tyrian purple, and
was buried in 814 in a shroud of the same color, which still exists (see
below). However, after the fall of Constantinople to the Ottoman Turks
in 1453, the color lost its imperial status. The great dye works of
Constantinople were destroyed, and gradually scarlet, made with dye from
the cochineal insect, became the royal color in Europe....
The Middle Ages and Renaissance
In
1464, Pope Paul II decreed that cardinals should no longer wear Tyrian
purple, and instead wear scarlet, from kermes and alum,[43] since the
dye from Byzantium was no longer available. Bishops and archbishops, of a
lower status than cardinals, were assigned the color purple, but not
the rich Tyrian purple. They wore cloth dyed first with the less
expensive indigo blue, then overlaid with red made from kermes
dye.[44][45]
While purple was worn less frequently by Medieval
and Renaissance kings and princes, it was worn by the professors of many
of Europe's new universities. Their robes were modeled after those of
the clergy, and they often wore square/violet or purple/violet caps and
robes, or black robes with purple/violet trim. Purple/violet robes were
particularly worn by students of divinity.
Purple and/or violet
also played an important part in the religious paintings of the
Renaissance. Angels and the Virgin Mary were often portrayed wearing
purple or violet robes....
18th and 19th centuries
In
the 18th century, purple was still worn on occasion by Catherine the
Great and other rulers, by bishops and, in lighter shades, by members of
the aristocracy, but rarely by ordinary people, because of its high
cost. But in the 19th century, that changed.
In 1856, an
eighteen-year-old British chemistry student named William Henry Perkin
was trying to make a synthetic quinine. His experiments produced instead
the first synthetic aniline dye, a purple shade called mauveine,
shortened simply to mauve. It took its name from the mallow flower,
which is the same color.[46] The new color quickly became fashionable,
particularly after Queen Victoria wore a silk gown dyed with mauveine to
the Royal Exhibition of 1862. Prior to Perkin's discovery, mauve was a
color which only the aristocracy and rich could afford to wear. Perkin
developed an industrial process, built a factory, and produced the dye
by the ton, so almost anyone could wear mauve. It was the first of a
series of modern industrial dyes which completely transformed both the
chemical industry and fashion.[47]
Purple was popular with the
pre-Raphaelite painters in Britain, including Arthur Hughes, who loved
bright colors and romantic scenes....
20th and 21st centuries
At
the turn of the century, purple was a favorite color of the Austrian
painter Gustav Klimt, who flooded his pictures with sensual purples and
violets.
In the 20th century, purple retained its historic
connection with royalty; George VI (1896–1952), wore purple in his
official portrait, and it was prominent in every feature of the
coronation of Elizabeth II in 1953, from the invitations to the stage
design inside Westminster Abbey. But at the same time, it was becoming
associated with social change; with the Women's Suffrage movement for
the right to vote for women in the early decades of the century, with
Feminism in the 1970s, and with the psychedelic drug culture of the
1960s.
In the early 20th century, purple, green, and white were
the colors of the Women's Suffrage movement, which fought to win the
right to vote for women, finally succeeding with the 19th Amendment to
the U.S. Constitution in 1920. Later, in the 1970s, in a tribute to the
Suffragettes, it became the color of the women's liberation
movement.[48]
In the concentration camps of Nazi Germany,
prisoners who were members of non-conformist religious groups, such as
the Jehovah's Witnesses, were required to wear a purple triangle.[49]
During
the 1960s and early 1970s, it was also associated with counterculture,
psychedelics, and musicians like Jimi Hendrix with his 1967 song "Purple
Haze", or the English rock band of Deep Purple which formed in 1968.
Later, in the 1980s, it was featured in the song and album Purple Rain
(1984) by the American musician Prince.
The Purple Rain Protest
was a protest against apartheid that took place in Cape Town, South
Africa on 2 September 1989, in which a police water cannon with purple
dye sprayed thousands of demonstrators. This led to the slogan The
Purple Shall Govern.
The violet or purple necktie became very
popular at the end of the first decade of the 21st century, particularly
among political and business leaders. It combined the assertiveness and
confidence of a red necktie with the sense of peace and cooperation of a
blue necktie, and it went well with the blue business suit worn by most
national and corporate leaders....
In science and nature
Optics
The
meanings of the color terms violet and purple varies even among native
speakers of English, for example between United Kingdom and United
States [51] Since this Wikipedia page contains contributions from
authors from different countries and different native languages, it is
likely to be not consistent in the use of the color terms violet and
purple. According to some speakers/authors of English, purple, unlike
violet, is not one of the colors of the visible spectrum.[52] It was not
one of the colors of the rainbow identified by Isaac Newton, although
in earlier versions of Newton's work the word purple was used where
violet was used in the final version. According to some authors, purple
does not have its own wavelength of light. For this reason, it is
sometimes called a non-spectral color. It exists in culture and art, but
not, in the same way that violet does, in optics. According to some
speakers of English, purple is simply a combination, in various
proportions, of two primary colors, red and blue.[53] According to other
speakers of English, the same range of colors is called violet.[54]
In
some textbooks of color theory, and depending on the
geographical-cultural origin of the author, a "purple" is defined as any
non-spectral color between violet and red (excluding violet and red
themselves).[16] The spectral colors violet and indigo would in that
case not be purples. For other speakers of English, these colors are
purples.
In the traditional color wheel long used by painters,
purple is placed between crimson and violet.[55] However, also here
there is much variation in color terminology depending on cultural
background of the painters and authors, and sometimes the term violet is
used and placed in between red and blue on the traditional color wheel.
In a slightly different variation, on the color wheel, purple is placed
between magenta and violet. This shade is sometimes called electric
purple (See shades of purple).[56]
In the RGB color model, named
for the colors red, green, and blue, used to create all the colors on a
computer screen or television, the range of purples is created by mixing
red and blue light of different intensities on a black screen. The
standard HTML color purple is created by red and blue light of equal
intensity, at a brightness that is halfway between full power and
darkness.
In color printing, purple is sometimes represented by
the color magenta, or sometimes by mixing magenta with red or blue. It
can also be created by mixing just red and blue alone, but in that case
the purple is less bright, with lower saturation or intensity. A less
bright purple can also be created with light or paint by adding a
certain quantity of the third primary color (green for light or yellow
for pigment).
On a chromaticity diagram, the straight line
connecting the extreme spectral colors (red and violet) is known as the
line of purples (or 'purple boundary'); it represents one limit of human
color perception. The color magenta used in the CMYK printing process
is near the center of the line of purples, but most people associate the
term "purple" with a somewhat bluer tone, such as is displayed by the
color "electric purple" (a color also directly on the line of purples),
shown below. Some common confusion exists concerning the color names
"purple" and "violet". Purple is a mixture of red and blue light,
whereas violet is a spectral color.
On the CIE xy chromaticity
diagram, violet is on the curved edge in the lower left, while purples
are on the straight line connecting the extreme colors red and violet;
this line is known as the line of purples, or the purple line.[57][58]
On a computer or television screen, purple colors are created by mixing
red and blue light. This is called the RGB color model.
The CIE xy chromaticity diagram
Pigments
Hematite and manganese are the oldest pigments used for the color
purple. They were used by Neolithic artists in the form of sticks, like
charcoal, or ground and powdered and mixed with fat, and used as a
paint. Hematite is a reddish iron oxide which, when ground coarsely,
makes a purple pigment. One such pigment is caput mortuum, whose name is
also used in reference to mummy brown. The latter is another pigment
containing hematite and historically produced with the use of mummified
corpses.[59] Some of its compositions produce a purple color and may be
called "mummy violet".[60] Manganese was also used in Roman times to
color glass purple.[61]
Han purple was the first synthetic purple
pigment, invented in China in about 700 BC. It was used in wall
paintings and pottery and other applications. In color, it was very
close to indigo, which had a similar chemical structure. Han purple was
very unstable, and sometimes was the result of the chemical breakdown of
Han blue.
During the Middle Ages, artists usually made purple by
combining red and blue pigments; most often blue azurite or
lapis-lazuli with red ochre, cinnabar, or minium. They also combined
lake colors made by mixing dye with powder; using woad or indigo dye for
the blue, and dye made from cochineal for the red.[62]
Cobalt violet was the first modern synthetic color in the purple family,
manufactured in 1859. It was found, along with cobalt blue, in the
palette of Claude Monet, Paul Signac, and Georges Seurat. It was stable,
but had low tinting power and was expensive, so quickly went out of
use.[63]
Manganese violet was a stronger color than cobalt violet, and replaced it on the market.
Quinacridone violet, one of a modern synthetic organic family of
colors, was discovered in 1896 but not marketed until 1955. It is sold
today under a number of brand names.
Manganese pigments were used in the neolithic paintings in the Lascaux cave, France.
Hematite was often used as the red-purple color in the cave paintings of Neolithic artists.
A sample of purpurite, or manganese phosphate, from the Packrat Mine in Southern California.
A swatch of cobalt violet, popular among the French impressionists.
Manganese violet is a synthetic pigment invented in the mid-19th century.
Quinacridone violet, a synthetic organic pigment sold under many different names.
Dyes
The
most famous purple dye in the ancient world was Tyrian purple, made
from a type of sea snail called the murex, found around the
Mediterranean. (See history section above).[52]
In western
Polynesia, residents of the islands made a purple dye similar to Tyrian
purple from the sea urchin. In Central America, the inhabitants made a
dye from a different sea snail, the purpura, found on the coasts of
Costa Rica and Nicaragua. The Mayans used this color to dye fabric for
religious ceremonies, while the Aztecs used it for paintings of
ideograms, where it symbolized royalty.[62]
In the Middle Ages,
those who worked with blue and black dyes belonged to separate guilds
from those who worked with red and yellow dyes, and were often forbidden
to dye any other colors than those of their own guild.[64] Most purple
fabric was made by the dyers who worked with red, and who used dye from
madder or cochineal, so Medieval violet colors were inclined toward
red.[citation needed]
Orcein, or purple moss, was another common
purple dye. It was known to the ancient Greeks and Hebrews, and was made
from a Mediterranean lichen called archil or dyer's moss (Roccella
tinctoria), combined with an ammoniac, usually urine. Orcein began to
achieve popularity again in the 19th century, when violet and purple
became the color of demi-mourning, worn after a widow or widower had
worn black for a certain time, before he or she returned to wearing
ordinary colors.[65]
From the Middle Ages onward, purple dyes for
the clothing of common people were often made from the blackberry or
other red fruit of the genus rubus, or from the mulberry. All of these
dyes were more reddish than bluish, and faded easily with washing and
exposure to sunlight.
A popular new dye which arrived in Europe
from the New World during the Renaissance was made from the wood of the
logwood tree (Haematoxylum campechianum), which grew in Spanish Mexico.
Depending on the different minerals added to the dye, it produced a
blue, red, black or, with the addition of alum, a purple color, It made a
good color, but, like earlier dyes, it did not resist sunlight or
washing.
In the 18th century, chemists in England, France and
Germany began to create the first synthetic dyes. Two synthetic purple
dyes were invented at about the same time. Cudbear is a dye extracted
from orchil lichens that can be used to dye wool and silk, without the
use of mordant. Cudbear was developed by Dr Cuthbert Gordon of Scotland:
production began in 1758, The lichen is first boiled in a solution of
ammonium carbonate. The mixture is then cooled and ammonia is added and
the mixture is kept damp for 3–4 weeks. Then the lichen is dried and
ground to powder. The manufacture details were carefully protected, with
a ten-feet high wall being built around the manufacturing facility, and
staff consisting of Highlanders sworn to secrecy.
French purple
was developed in France at about the same time. The lichen is extracted
by urine or ammonia. Then the extract is acidified, the dissolved dye
precipitates and is washed. Then it is dissolved in ammonia again, the
solution is heated in air until it becomes purple, then it is
precipitated with calcium chloride; the resulting dye was more solid and
stable than other purples.
Cobalt violet is a synthetic pigment
that was invented in the second half of the 19th century, and is made by
a similar process as cobalt blue, cerulean blue and cobalt green. It is
the violet pigment most commonly used today by artists. In spite of its
name, this pigment produces a purple rather than violet color [51]
Mauveine,
also known as aniline purple and Perkin's mauve, was the first
synthetic organic chemical dye,[66][67] discovered serendipitously in
1856. Its chemical name is
3-amino-2,±9-dimethyl-5-phenyl-7-(p-tolylamino)phenazinium acetate.
Fuchsine was another synthetic dye made shortly after mauveine. It produced a brilliant fuchsia color.
In
the 1950s, a new family of purple and violet synthetic organic pigments
called quinacridone came onto the market. It had originally been
discovered in 1896, but were not synthetized until 1936, and not
manufactured until the 1950s. The colors in the group range from deep
red to bluish purple in color, and have the molecular formula
C20H12N2O2. They have strong resistance to sunlight and washing, and are
widely used today in oil paints, water colors, and acrylics, as well as
in automobile coatings and other industrial coatings.
Blackberries were sometimes used to make purple dye in the Middle Ages.
This lichen, growing on a tree in Scotland, was used in the 18th century to make a common purple dye called Cudbear.
A sample of silk dyed with the original mauveine dye.
A sample of fuchsine dye
Animals
The male violet-backed starling sports a very bright, iridescent purple plumage.
The purple frog is a species of amphibian found in India.
Pseudanthias pascalus or purple queenfish.
The purple sea urchin from Mexico.
A purple heron in flight (South Africa).
A purple finch (North America).
The Lorius domicella, or purple-naped lory, from Indonesia.
Anthocyanins
Certain
grapes, eggplants, pansies and other fruits, vegetables and flowers may
appear purple due to the presence of natural pigments called
anthocyanins. These pigments are found in the leaves, roots, stems,
vegetables, fruits and flowers of all plants. They aid photosynthesis by
blocking harmful wavelengths of light that would damage the leaves. In
flowers, the purple anthocyanins help attract insects who pollinate the
flowers. Not all anthocyanins are purple; they vary in color from red to
purple to blue, green, or yellow, depending upon the level of their pH.
The purple colors of this cauliflower, grapes, fruits, vegetables and
flowers comes from natural pigments called anthocyanins.
Anthocyanins range in color from red to purple to green, blue and yellow, depending upon the level of their pH.
Anthocyanins also account for the purple color in these copper beech trees, and in purple autumn leaves.
Anthocyanins produce the purple color in blood oranges.
Purple pansy
A purple pansy.
"Blue" hydrangea is often actually purple.
"Blue" hydrangea is often actually purple.
Plants and flowers
Purple needlegrass is the state grass of California.
An artichoke flower in blossom in Dalat, Vietnam
Iris germanica flowers
Syringa vulgaris, or lilac blossoms
Medicago sativa, known as alfalfa in the U.S. and lucerne in the U.K.
The Aster alpinus, or alpine aster, is native to the European
mountains, including the Alps, while a subspecies is found in Canada and
the United States.
Lavender flowers.
A purple rose.
Wisteria is a pale purple color.
Wisteria is a pale purple color.
salsify
...
Mythology
Julius
Pollux, a Greek grammarian who lived in the second century AD,
attributed the discovery of purple to the Phoenician god and guardian of
the city of Tyre, Heracles.[72] According to his account, while walking
along the shore with the nymph Tyrus, the god's dog bit into a murex
shell, causing his mouth to turn purple. The nymph subsequently
requested that Heracles create a garment for her of that same color,
with Heracles obliging her demands giving birth to Tyrian
purple.[72][46]
Associations and symbolism
Royalty
In
Europe, since the time that the Roman emperors wore a Tyrian purple
(purpura) toga praetexta, purple has been the color most associated with
power and royalty.[52] The British Royal Family and other European
royalty still use it as a ceremonial color on special occasions.[73] In
Japan, purple is associated with the emperor and Japanese
aristocracy.[4]
A purple postage stamp honored Queen Elizabeth II in 1958
Queen Margrethe II of Denmark in 2010.
Piety, faith, penitence, and theology
In
the West, purple or violet is the color most associated with piety and
religious faith.[73] In AD 1464, shortly after the Muslim conquest of
Constantinople, which terminated the supply of Tyrian purple to Roman
Catholic Europe, Pope Paul II decreed that cardinals should henceforth
wear scarlet instead of purple, the scarlet being dyed with expensive
cochineal. Bishops were assigned the color amaranth, being a pale and
pinkish purple made then from a less-expensive mixture of indigo and
cochineal.
In the Latin Rite of the Roman Catholic liturgy,
purple symbolizes penitence; Anglican and Catholic priests wear a purple
stole when they hear confession and a purple stole and chasuble during
Advent and Lent. Since the Second Vatican Council of 1962–5, priests may
wear purple vestments, but may still wear black ones, when officiating
at funerals. The Roman Missal permits black, purple (violet), or white
vestments for the funeral Mass. White is worn when a child dies before
the age of reason. Students and faculty of theology also wear purple
academic dress for graduations and other university ceremonies.
Purple is also often worn by senior pastors of Protestant churches and bishops of the Anglican Communion.
In the Roman Catholic Church, cardinals now wear scarlet and bishops wear amaranth.
Katharine Jefferts Schori, Presiding Bishop of the Episcopal Church of the United States
The
color purple is also associated with royalty in Christianity, being one
of the three traditional offices of Jesus Christ, i. e. king, although
such a symbolism was assumed from the earlier Roman association or at
least also employed by the ancient Romans.
Vanity, extravagance, individualism
In
Europe and America, purple is the color most associated with vanity,
extravagance, and individualism. Among the seven major sins, it
represents vanity. It is a color which is used to attract attention.[74]
The artificial, materialism and beauty
Purple
is the color most often associated with the artificial and the
unconventional. It is the major color that occurs the least frequently
in nature, and was the first color to be synthesized.[75]
Ambiguity and ambivalence
Purple
is the color most associated with ambiguity. Like other colors made by
combining two primary colors, it is seen as uncertain and equivocal.[76]
Mourning
In
Britain, purple is sometimes associated with mourning. In Victorian
times, close relatives wore black for the first year following a death
("deep mourning"), and then replaced it with purple or dark green
trimmed with black. This is rarely practised today.[77]
In culture and society
Asian culture
The Chinese word for purple, zi, is connected with the North Star,
Polaris, or zi Wei in Chinese. In Chinese astrology, the North Star was
the home of the Celestial Emperor, the ruler of the heavens. The area
around the North Star is called the Purple Forbidden Enclosure in
Chinese astronomy. For that reason the Forbidden City in Beijing was
also known as the Purple Forbidden City (zi Jin cheng).
Purple
was a popular color introduced into Japanese dress during the Heian
period (794–1185). The dye was made from the root of the alkanet plant
(Anchusa officinalis), also known as murasaki in Japanese. At about the
same time, Japanese painters began to use a pigment made from the same
plant.[78]
See also: Traditional colors of Japan § Violet series
In Thailand, widows in mourning wear the color purple. Purple is also
associated with Saturday on the Thai solar calendar....
Engineering
The
color purple plays a significant role in the traditions of engineering
schools across Canada.[citation needed] Purple is also the color of the
Engineering Corp in the British Military.[citation needed]
Idioms and expressions
Purple prose refers to pretentious or overly embellished writing. For
example, a paragraph containing an excessive number of long and unusual
words is called a purple passage.
Born to the purple means
someone who is born into a life of wealth and privilege. It originally
was used to describe the rulers of the Byzantine Empire.
A purple
patch is a period of exceptional success or good luck.[79] The origins
are obscure, but it may refer to the symbol of success of the Byzantine
Court. Bishops in Byzantium wore a purple patch on their costume as a
symbol of rank.
Purple haze refers to a state of mind induced by psychedelic drugs, particularly LSD.[80]
Wearing purple is a military slang expression in the U.S., Canada and
the U.K. for an officer who is serving in a joint assignment with
another service, such as an Army officer on assignment to the Navy. The
officer is symbolically putting aside his or her traditional uniform
color and exclusive loyalty to their service during the joint
assignment, though in fact they continue to wear their own service's
uniform.[81]
Purple squirrel is a term used by employment
recruiters to describe a job candidate with precisely the right
education, experience, and qualifications that perfectly fits a job's
multifaceted requirements. The assumption is that the perfect candidate
is as rare as a real-life purple squirrel.
Military
The Purple Heart is a United States military decoration awarded in the
name of the President to those who have been wounded or killed during
their service.
Politics
In United States politics, a
purple state is a state roughly balanced between Republicans (generally
symbolized by red in the 21st century) and Democrats (symbolized by
blue).
In the politics of the Netherlands, Purple (Dutch: paars)
means a coalition government consisting of liberals and social democrats
(symbolized by the colors blue and red, respectively), as opposed to
the more common coalitions of the Christian Democrats with one of the
other two. Between 1994 and 2002 there were two Purple cabinets, both
led by Prime Minister Wim Kok.
In the politics of Belgium, as
with the Netherlands, a purple government includes liberal and
social-democratic parties in coalition. Belgium was governed by Purple
governments from 1999 to 2007 under the leadership of Prime Minister Guy
Verhofstadt.
Purple is the primary color used by many European
and American political parties, including Volt Europa, the UK
Independence Party, the Social Democrats in the Republic of Ireland, the
Liberal People's Party in Norway, and the United States Pirate Party.
The Left party in Germany, whose primary color is red, is traditionally
portrayed in purple on election maps to distinguish it from the Social
Democratic Party of Germany.[citation needed]
In the United
Kingdom, the color scheme for the suffragette movement in Britain and
Ireland was designed with purple for loyalty and dignity, white for
purity, and green for hope.[82][83][84]
Rhyme
Purple was a
central motif in the career of the musician Prince. His 1984 film and
album Purple Rain is one of his best-known works. The title track is
Prince's signature song and was nearly always played in concert. Prince
encouraged his fans to wear purple to his concerts.[85][86]
In the English language, the word "purple" has only one perfect rhyme,
curple. Others are obscure perfect rhymes, such as hirple.
Robert Burns rhymes purple with curple in his Epistle to Mrs. Scott.
Examples of imperfect rhymes or non-word rhymes with purple:
In the song Grace Kelly by Mika the word purple is rhymed with "hurtful".
In his hit song "Dang Me," Roger Miller sings these lines:
"Roses are red, violets are purple
Sugar is sweet and so is maple surple"
Sexuality
Purple
is sometimes associated with the lesbian, gay, bisexual, and
transgender (LGBT) community.[citation needed] It is the symbolic color
worn on Spirit Day, a commemoration that began in 2010 to show support
for young people who are bullied because of their sexual
orientation.[87][88] Purple is closely associated with bisexuality,
largely in part to the bisexual pride flag which combines pink –
representing homosexuality – and blue – representing heterosexuality –
to create the bisexual purple.[citation needed] The purple hand is
another symbol sometimes used by the LGBT community during parades and
demonstrations.
Sports and games
The National Basketball
Association's Los Angeles Lakers, Phoenix Suns and Sacramento Kings use
purple as their primary color.
In the Indian Premier League, purple is the primary color of the Kolkata Knight Riders.
In Major League Baseball, purple is one of the primary colors for the Colorado Rockies.
In the National Football League, the Minnesota Vikings and Baltimore Ravens use purple as main colors.
The Australian Football League's Fremantle Football Club use purple as one of their primary colors.
In association football (soccer), Italian Serie A club ACF Fiorentina,
Belgian Pro League club and former Europa League winner R.S.C.
Anderlecht, French Ligue 1 club Toulouse FC and Ligue 2 club FC Istres,
Spanish La Liga club Real Valladolid, Austrian Football Bundesliga club
FK Austria Wien, Hungarian Nemzeti Bajnokság I club Újpest FC, Slovenian
PrvaLiga club NK Maribor, former Romanian Liga I clubs FC Politehnica
Timișoara and FC Argeș Pitești, Andorran Primera Divisió club CE
Principat, German club Tennis Borussia Berlin, Italian club A.S.D.
Legnano Calcio 1913, Swedish club Fässbergs IF, Japanese club Kyoto
Sanga, Australian A-League Club Perth Glory and American Major League
Soccer club Orlando City use purple as one of their primary colors.
The Melbourne Storm from Australia's National Rugby League use purple as one of their primary colors.
Costa Rica's Primera División soccer team Deportivo Saprissa's main
color is purple (actually a burgundy like shade), and their nickname is
the "Monstruo Morado", or "Purple Monster".
In tennis, the official colors of the Wimbledon championships are deep green and purple (traditionally called mauve).
In American college athletics, Louisiana State University, Kansas State
University, Texas Christian University, the University of Central
Arkansas, Northwestern University, the University of Washington, and
East Carolina University all have purple as one of their main team
colors.
The University of Western Ontario in London, Canada, and
Bishop's University in Sherbrooke, Canada, have purple as one of its
main team colors.
Purple is the color of the ball in Snooker Plus with a 10-point value.
In the game of pool, purple is the color of the 4-solid and the 12-striped balls.
Cadbury logo as displayed at Cadbury World in Bournville, England
Business
The
British chocolate company Cadbury chose purple as it was Queen
Victoria's favourite color.[89] The company trademarked the color purple
for chocolates with registrations in 1995[90] and 2004.[91] However,
the validity of these trademarks is the matter of an ongoing legal
dispute following objections by Nestlé.[92]
Emblem of King Alfonso IX
of León (1180-1230) displayed in the 12th century Tumbo A manuscript in
the Santiago de Compostela Cathedral, Galicia.
In flags
Purple or violet appear in the flags of only two modern sovereign
nations, and are merely ancillary colors in both cases. The Flag of
Dominica features a sisserou parrot, a national symbol, while the Flag
of Nicaragua displays a rainbow in the center, as part of the coat of
arms of Nicaragua.
The lower band of the flag of the second
Spanish republic (1931–39) was colored a tone of purple, to represent
the common people as opposed to the red of the Spanish monarchy, unlike
other nations of Europe where purple represented royalty and red
represented the common people.[93]
In Japan, the prefecture of Tokyo's flag is purple, as is the flag of Ichikawa.
Porpora, or purpure, a shade of purple, was added late to the list of
colors of European heraldry. A purple lion was the symbol of the old
Spanish Kingdom of León (910–1230), and it later appeared on the flag of
Spain, when the Kingdom of Castile and Kingdom of León merged."
(wikipedia.org)
"J.A. Bauer Pottery is an
American pottery that was founded in Paducah, Kentucky[1] in 1895 and
operated for most of its life in Los Angeles, California.[2] It closed
in 1962....
History
In 1885, John Andrew "Andy"
Bauer[3] bought out Frank Parham's Paducah Pottery in Paducah, Kentucky,
a pottery whose main products were brown-glazed, hand-thrown wares
including crocks and jugs. J.A. Bauer moved his family to Los Angeles in
early 1909, and selected a new site for a pottery. J.A. Bauer Pottery
Company was built at 415-421 West Avenue 33 in Lincoln Heights,[3] an
area between Los Angeles and Pasadena, California. The first products
were the same products J.A. Bauer produced in Paducah. Demand from the
nursery trade added new products to the pottery's wares including flower
pots, garden ware, and planters.
J.A. Bauer ring ware vase
Louis
Ipsen was hired around 1912 as a designer, adding fancy redware items
to the pottery lines. Matterson (Matt) Carlton, an accomplished turner,
joined the company producing hand-thrown vases, rose jars, and carnation
vases for the nursery trade. In 1922, J. A. Bauer retired and in 1923
died.[2] One third of the company was sold to his daughter Eve, and her
husband Watson E. Bockman. The other two thirds was sold to Bernard
Bernheim. Bockman became president of the company. By 1928, Bockman
resigned and the heirs of Bernard Bernheim, sons Sam and Lynn Bernheim,
ran the company. In 1929 W. E. Bockman bought out the Bernheims and once
again became president of the company. Bockman hired ceramic engineer
Victor F. Houser to develop new glazes. "The introduction of Houser's
brilliant new colors on Ipsen's dishes proved a momentous event.",[3]
Around
1930, Bauer Pottery introduced California Colored Pottery.[3] Other
Southern California potteries producing solid colored earthenware
tableware and kitchenware products around the same time period as the
introduction of Bauer's California Colored Pottery were Gladding, McBean
& Co.'s Franciscan Ware, Metlox Manufacturing Company, Pacific Clay
Potteries' Hostess Ware, Vernon Kilns' Early California, and Catalina
Clay Products' Catalina Pottery. By 1933, the company added ridged or
"ring" dishes, including its distinctive Ringware line, named for the
concentric circles that mark the pieces.[2] In 1934, Fred Johnson, Matt
Carlton's nephew and an accomplished hand-thrower formerly with the
Niloak Pottery in Benton, Arkansas, joined the company. Fred Johnson
added new shapes to Bauer Pottery's table and art ware lines.
In
1938, Bauer Pottery sought to expand their market to the East coast by
purchasing, and converting to a pottery, an old winery in Atlanta,
Georgia. W. E. Bockman died before Bauer Atlanta was opened. John
Herbert (Herb) Brutsche took over management of the Atlanta plant, and
James (Jim) Bockman became the Los Angeles plant's general manager. A
line of art pottery produced in the Atlanta plant was designed by
industrial designer Russel Wright in 1945. The Russel Wright Bauer line
was not successful and was discontinued shortly after its introduction.
The Bauer Atlanta plant was converted into a sanitary ware production
plant, Georgia Sanitary Pottery.
In 1962, Bauer Pottery ceased
operations;[2] Eva Bockman shut down Bauer Pottery rather than settle a
general labor strike which began in the fall of 1961.[3]
Revival
Bauer
Pottery was revived in 2000 by collector Janek Boniecki in a small
ceramic studio outside Los Angeles. The new company introduced a new
line, Bauer 2000, featuring pieces based on original shapes and colors
from the 1930s and 1940s. Unable to locate any original Bauer dies or
molds, Boniecki reverse-engineered the new line from pieces from his own
collection and other vintage purchases.[2][4]
Cultural references
In The Hand That Rocks the Cradle (film), a collection of Bauer ring dinnerware is used in the kitchen.
In Mildred Pierce, Mildred uses Bauer mixing bowls.
In the television show The New Normal, Bryan and David's home is
decorated with Bauer pottery, and they use Bauer ringware as their
dinnerware." (wikipedia.org)
"Ceramic art is
art made from ceramic materials, including clay. It may take forms
including artistic pottery, including tableware, tiles, figurines and
other sculpture. As one of the plastic arts, ceramic art is one of the
visual arts. While some ceramics are considered fine art, as pottery or
sculpture, most are considered to be decorative, industrial or applied
art objects. Ceramics may also be considered artefacts in archaeology.
Ceramic art can be made by one person or by a group of people. In a
pottery or ceramic factory, a group of people design, manufacture and
decorate the art ware. Products from a pottery are sometimes referred to
as "art pottery".[1] In a one-person pottery studio, ceramists or
potters produce studio pottery.
The word "ceramics" comes from
the Greek keramikos (κεραμεικός), meaning "pottery", which in turn comes
from keramos (κέραμος) meaning "potter's clay".[2] Most traditional
ceramic products were made from clay (or clay mixed with other
materials), shaped and subjected to heat, and tableware and decorative
ceramics are generally still made this way. In modern ceramic
engineering usage, ceramics is the art and science of making objects
from inorganic, non-metallic materials by the action of heat. It
excludes glass and mosaic made from glass tesserae.
There is a
long history of ceramic art in almost all developed cultures, and often
ceramic objects are all the artistic evidence left from vanished
cultures, like that of the Nok in Africa over 2,000 years ago. Cultures
especially noted for ceramics include the Chinese, Cretan, Greek,
Persian, Mayan, Japanese, and Korean cultures, as well as the modern
Western cultures.
Elements of ceramic art, upon which different
degrees of emphasis have been placed at different times, are the shape
of the object, its decoration by painting, carving and other methods,
and the glazing found on most ceramics....
Materials
Main articles: Earthenware, Stoneware, Porcelain, and Bone china
Different
types of clay, when used with different minerals and firing conditions,
are used to produce earthenware, stoneware, porcelain and bone china
(fine china).
Earthenware is pottery that has not been fired
to vitrification and is thus permeable to water.[3] Many types of
pottery have been made from it from the earliest times, and until the
18th century it was the most common type of pottery outside the far
East. Earthenware is often made from clay, quartz and feldspar.
Terracotta, a type of earthenware, is a clay-based unglazed or glazed
ceramic,[4] where the fired body is porous.[5][6][7][8] Its uses include
vessels (notably flower pots), water and waste water pipes, bricks, and
surface embellishment in building construction. Terracotta has been a
common medium for ceramic art (see below).
Stoneware is a
vitreous or semi-vitreous ceramic made primarily from stoneware clay or
non-refractory fire clay.[9] Stoneware is fired at high
temperatures.[10] Vitrified or not, it is nonporous;[11] it may or may
not be glazed.[12] One widely recognised definition is from the Combined
Nomenclature of the European Communities, a European industry standard
states "Stoneware, which, though dense, impermeable and hard enough to
resist scratching by a steel point, differs from porcelain because it is
more opaque, and normally only partially vitrified. It may be vitreous
or semi-vitreous. It is usually coloured grey or brownish because of
impurities in the clay used for its manufacture, and is normally
glazed."[11]
Porcelain is a ceramic material made by heating
materials, generally including kaolin, in a kiln to temperatures between
1,200 and 1,400 °C (2,200 and 2,600 °F). The toughness, strength and
translucence of porcelain, relative to other types of pottery, arises
mainly from vitrification and the formation of the mineral mullite
within the body at these high temperatures. Properties associated with
porcelain include low permeability and elasticity; considerable
strength, hardness, toughness, whiteness, translucency and resonance;
and a high resistance to chemical attack and thermal shock. Porcelain
has been described as being "completely vitrified, hard, impermeable
(even before glazing), white or artificially coloured, translucent
(except when of considerable thickness), and resonant". However, the
term porcelain lacks a universal definition and has "been applied in a
very unsystematic fashion to substances of diverse kinds which have only
certain surface-qualities in common".[13]
Bone china (fine
china) is a type of soft-paste porcelain that is composed of bone ash,
feldspathic material, and kaolin. It has been defined as ware with a
translucent body containing a minimum of 30% of phosphate derived from
animal bone and calculated calcium phosphate.[11][clarification needed]
Developed by English potter Josiah Spode, bone china is known for its
high levels of whiteness and translucency,[14] and very high mechanical
strength and chip resistance.[15] Its high strength allows it to be
produced in thinner cross-sections than other types of porcelain.[14]
Like stoneware it is vitrified, but is translucent due to differing
mineral properties.[16] From its initial development and up to the later
part of the twentieth century, bone china was almost exclusively an
English product, with production being effectively localised in
Stoke-on-Trent.[15] Most major English firms made or still make it,
including Mintons, Coalport, Spode, Royal Crown Derby, Royal Doulton,
Wedgwood and Worcester. In the UK, references to "china" or "porcelain"
can refer to bone china, and "English porcelain" has been used as a term
for it, both in the UK and around the world.[17] Fine china is not
necessarily bone china, and is a term used to refer to ware which does
not contain bone ash...
Studio pottery
Main article: Studio pottery
Studio
pottery is pottery made by amateur or professional artists or artisans
working alone or in small groups, making unique items or short runs.
Typically, all stages of manufacture are carried out by the artists
themselves.[21] Studio pottery includes functional wares such as
tableware, cookware and non-functional wares such as sculpture. Studio
potters can be referred to as ceramic artists, ceramists, ceramicists or
as an artist who uses clay as a medium. Much studio pottery is
tableware or cookware but an increasing number of studio potters produce
non-functional or sculptural items. Some studio potters now prefer to
call themselves ceramic artists, ceramists or simply artists. Studio
pottery is represented by potters all over the world. ...
Pottery in Germany
German pottery has its roots in the alchemistry laboratories searching for gold production.
Royal Porcelain Factory, Berlin
Meissen porcelain
Nymphenburg porcelain[60]
Hutschenreuther" (wikipedia.org)