indigo wax
A cylindrical solid made from indigo dye froth, often boiled with caustic soda; used as a pigment in traditional painting and crafts.
Indigo wax is sometimes used as a pigment in Japanese painting.
Indigo wax is made from the froth produced during the indigo dyeing process.
Compound of 藍 (indigo) and 蝋 (wax), referring to the waxy solid produced from indigo dye froth.