Ammonium Sulfate

Ammonium Sulfate is a salt that forms a mild acid when used for dyeing protein fibers.  It is a fixative and an alternative to vinegar or citric acid because it allows a slower release of acid, encouraging uniformity in shade for light to medium colors.  It can be an eye and skin irritant, so wear gloves and eye protection; and use a dust mask when exposed to the dry powder.  Application: One tablespoon ammonium sulfate per one pound of wool, silk, mohair, etc., in 2.5 gallons of water.