Madder dyeing of cotton with mordant
Tinte de rubia con mordiente sobre algodón
- Date
- c. 2500 BCE · confidence low
- Place
- Mohenjo-daro, Sindh, Pakistan
- Credited to
- Indus Valley Civilisation
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
A fragment of cotton cloth stuck to a silver vessel from Mohenjo-daro retains red colour from madder root, a dye that only fixes to cotton with a metallic mordant such as alum. It is the earliest evidence of the Indian art of mordant dyeing that would dominate the textile trade for millennia.
The use of a mordant is inferred from the colour fixation on the cotton; there is no conclusive chemical analysis of the original mordant.
What it led to
- cotton fabrics dyed as an export commodity
- practical chemistry of alum and iron mordants
- Indian tradition of fast, washable dyes