Question

What is the great demand indian indigo in foreign markets

Answer 1

In the middle ages, indigo was the only dye of blue available in Europe. Ultramarine, made from the no less expensive and hard-to-get lapislazuli, was suitable for painting but not for dying clothes. Within Europe, the same chemical that is extracted from the proper indigo plant could be won from the locally planted ‘dyer’s woad’, however, with only a tenth of the concentration of the indido plant.
In the late 19th century German scientists managed to produce that colour synthetically; and other blue dyes have been discovered throughout modernity.

Answer 2

Indigo was in popular demand in Italy, France and Britain as a dye by the 13th century. However, due to its high price, attempts were made to replace it by another plant woad which was grown in Italy France, Britain, etc.

Also, the plant woad, which was grown in other countries, which they were replacing with Indian Indigo was of dull colour. The dull and pale colour of woad once again increased the demand for Indian Indigo.