Acid Dyes

ACID DYES are anionic, soluble in water, and are mostly used in an acidic bath. Acid dyes are used to colour protein fibres such as silk, wool, alpaca, feathers, mohair, angora, etc., as well as man-made Nylon, which is chemically related to silk. The acid component of the term comes into play because a very weak acid, such as household white vinegar or odourless Citric Acid, is used to reduce the pH of the dyebath, causing the dye to attach to the protein fibres. In contrast, when employing Fiber Reactive colours on cellulose materials, the dye bath must be alkaline.