Can you guess what is happening in this picture? Indigo is an important natural source of blue dye and has been since the 1700s. The textile industry in Europe was booming and the huge demand for Indigo led to it being called “blue gold”. The British established the cultivation of Indigo in Bengal, but did so in part by forcing growers to purchase land using borrowed funds. Unable to repay the loans, many lost their lands and their livelihood.Thousands refused to grow Indigo and in 1859 revolted in what is now Bangladesh.

Indigo is difficult to handle because it has to oxidize to produce the familiar deep blue colour. In the picture, the dye workers are folding yarn over and over in the dye to maximize the oxidation. It is then dried and used mainly as the blue thread in jeans and other garments.

Even Wordsworth got involved in the plight of indigo dye workers in his hometown of Cockermouth:

Doubtless, I should have then made common cause

With some who perished; haply perished too

A poor mistaken and bewildered offering

Unknown to those bare souls of miller blue