CLASS OF DYES
Acid dye -> used in an acidic dye bath, soluble in water, good fast to light.
Direct dye -> Soluble in water, moderately fast to light, poor wash fastness
Reactive dye -> water soluble, forms strong chemical bond with cellulostic and protein fibres. give bright colours, fast to washing (don't fade)
VAT dye -> not soluble in water, excellent wash and light fastness, best known vat dye is 'indigo', used to dye jeans.
Colour fastness is whether a fabric fades or not, factors affecting colour fastness of textile products are:
- dry cleaning