A great video from the V and A

Derived from the leaves of shrubs in the Indigofera family, indigo dye has been used for millennia in most regions of India to colour yarn and fabric (especially cotton) in shades of blue. Indigo is a substantive dye, fixing without the help of a mordant, but requires expertise to successfully prepare and use.

Sketching out the floral pattern for wax painting

After three dips the wax gets boiled off and this is the finished piece 

A block and paper backing, folded and ready to be clamped

Some of the results from a combination of three and four dips