A dye is a coloured substance having affinity to the substrate to which it is being applied. Most natural dyes are ______________.

Mordant dyes require a mordant, which improves the fastness of the dye against water, light and perspiration. The choice of mordant is very important as different mordants can change the final colour significantly. Most natural dyes are mordant dyes and there is, therefore, a large literature base describing dyeing techniques.