Beautiful blue glass Ball mason jar pre-Perfect in very good antique blown molded used condition with scattered air pockets in the glass. Ball script is the 1910-23 version with some oddity and known early production errors. It is called an outlined markings error with more errors not only widen lettering embossed, the block style MASON  is enlarged with leaning g letters some are taller or shorter than others, the right side of the letter M in leaning left the A is almost filled in, the top of the S is longer at the top and larger in length and width, the O is short and leaning to the right, the N is also enlarged , taller and leaning left and to the right on opposite sides. LL in Ball is also not shaped right, uneven, thicker wider in places. Early version Ball jar, perhaps a prototype, pre-perfect block letters. Also, the mark on the bottom is very odd. Large looped 3 like shape. The glass is wavy and a bit older looking than the others from the date of the Ball scripting. Before the word perfect was added. It comes with an old zinc Ball cap that is marked on the liner not the top, it reads FOR BALL ASON JARS GENUINE ZINC CAP on the white glass liner. Quart size rounded over shaped jar. Review photos for details. The air pockets in this jar add to its character, high raised slightly pushed up applied bottom ring with blown molded scar ring on the bottom. The cap is a dirt find that has been thoroughly cleaned with some calcium, scale deposits remain on the top of the cap, shows aging signs, rare early zinc cap version. The jar has been used but well cared for, clean with no chips, cracks, stains or cloudiness. Only notable use/age signs to the glass is a few scattered small surface scratches. Neat new and known rare errored authentic blue Ball Glass manufactured error. Guaranteed to be as listed and as in the photos.