Indigo is insoluble in both water and alcohol. Indigo is an organic pigment with a blackish blue, somewhat dull hue. The plants from which indigo can be obtained are found in many parts of the world. The plant that gives it its name, Indigofera tinctoria L., is native to India. As an artists pigment, indigo has been documented in Roman paintings from the 1st century AD, in early medieval miniatures, and in paintings from all periods of European relay painting. The oldest evidence, however, comes from excavations and has been dated to 3000 BC.
Note: The genuine Indian indigo has a typical inherent odor.
