Indigo was used in India, which was also the earliest major center for its production and processing. It was the primary supplier of Indigo to Europe as early as the Greco-Roman era. It is now grown, cultivated, processed and dyed in many countries - the main ones being Japan, China and Africa and of course still India.
I have found that many things have happened of late that has made my interest in Indigo grow for example I am attending the "Japanese Club" at Riverlea, a quilt shop here in Adelaide and the tutor talk about Indigo in Japan. When I visited China recently I visit a village named Wuzhen that produces Indigo fabrics - dyed, printed and stencilled. It was fascinating and I bought a few small pieces (photos below).
Indigo "cakes" - in a market China
My own shibori dyed Indigo
Detail - Random piecing - a new piece for an exhibition
Wuzhen village - CHina
Wuzhen - the Indigo village
Odd childrens fashions using Indigo fabrics