Dyes

Dyes have added colour to human goods since antiquity — the earliest authentic dyeing records survive in the tomb paintings of ancient Egypt, where mummy wrappings were coloured with saffron and indigo, a use also echoed in ancient Indian rock paintings. Indigo (Indigofera species, family Fabaceae) — specifically Indigofera tinctoria, native to India — was once grown across many Indian states but is now cultivated mainly in Tamil Nadu and Andhra Pradesh; its leaves yield a brilliant dark-blue dye that Asian, and especially Indian, dyers have used for over 4,000 years, prominently in temple and folk art such as Kalamkari, and for dyeing cotton, rayon and wool. Henna (Lawsonia inermis, family Lythraceae), indigenous to North Africa and South-West Asia and grown widely across India, especially Gujarat, Madhya Pradesh and Rajasthan, yields an orange dye from its leaves and young shoots whose principal colouring compound, lawsone, is harmless and causes no skin irritation, unlike many synthetic dyes; it has long been used to colour skin, hair and fingernails, to dye leather and horse-tails, and in hair dyes. Indigo cultivation also has a notable place in Indian political history: under British rule, farmers were forced to g …