Indigo is a blue dye which comes from the indigo (neel) plant. Indigo cultivation is thought to have existed in the Indus Valley civilization more than 5,000 years ago. Indigo happens to be among the oldest textile dyes. Indigofera tinctoria, is the botanical name of Indigo Plant from which the Indigo dye comes.
Its demand later spread far and wide and it was one of the major items of trade with Greeks and Romans. Later Arabs introduced it to the Mediterranean and the rest of Europe. They called it ‘a-nil’ meaning ‘the blue’ – the dye is still known as ‘nil’
Indigo became one of the most profitable trade commodities for the British in the sixteenth centuries. East India Company or the British rule, thrived on Indigo trade as it fetched them huge profits. Indigo, thus started to be called as “Blue Gold”.
Block Printing Process:
Block printers, carvers and dyers are all traditionally part of the Chhippa cast in India. Like most crafts in India the skill of block carving is passed down from father to son. After each wood block is carved they are soaked in mustard oil for up to a week to ensure the wood doesn’t crack when exposed to the dry conditions of the printing process.
Dabu is a smooth paste, which combines well sieved and soaked black earth, tree gum and a powder from wheat grains. The printer gently pats the wood block onto the dabu paste then quickly stamps it onto the fabric. This paste acts as a resist during the dyeing process.
The printer aligns the first block to the bottom left corner of the fabric and with incredibly precise hand eye coordination, that has been developed over years of block printing, gives a sharp tap the release the dabu paste onto the cloth.
A fine saw dust is scattered over the wet daub paste once it has been printed to prevent the design from smudging and seals the printed portion from the subsequent dyeing process. Once the sawdust has been scattered, the fabric is taken outside so the sun can dry it. This causes the sawdust and dabu paste to fuse together, creating a hard barrier that the dye can not penetrate.
The dabu printed cloth is next immersed in the deep vat of indigo dye. Natural indigo, from the indigo plant indigofera tinctoria, is not water soluble. It is purchased in blocks, ground into a powder and soaked before fermenting in an underground vat containing a strong alkaline lime powder and water. The strong alkaline reduces the indigo dye, removing oxygen from the liquid and so making the color chemically available to bond to the cloth. When the cloth is removed from the vat it is green in color, though as it comes into contact with the air (oxygen) the cloth develops into a rich blue tone. The cloth is dipped repeatedly into the indigo vat to achieve darker shades of blue, drying thoroughly between each successive immersion.
After the fabric has achieved the right shade of blue, the cloth is stretched out in the sun to dry.
Each piece of indigo fabric tells a story of where it comes from in that it’s end colour can be influenced from anything from the weather conditions of the time at dyeing to the pH levels in the dye vat to the minerals in the water or the consistency of the dabu paste. However it is in these uncontrollable elements that the beauty of indigo dyed fabrics lies.