For use as a Modifier
Commonly used to darken or 'sadden' colours. 1 or 2 teaspoons is sufficient to dramatically change the colour of a dye bath.
For use as a Mordant (fixer)
Always use in small quantities as higher strengths can weaken fibres. Iron as a mordant will greatly improve fibres light and washfastness
Iron Sulphate is harmful if ingested and can cause irritation to skin and eyes so should always be handled with care and kept out of reach of children.