This pigment is from India and derived from the plant Indigofera tinctoria.
Indigo has a long, long history and contains some unpleasant moments from the era of the Empire where slave labour was used in it's intensive and then unpleasant method of production. Used in Peru in 4000 BC, mentioned by Pliny the Elder it has passed through human history in fairly constant use until relatively recently when it was replaced by synthetic dyes and pigments, a lump of genuine Indigo dye from India is shown opposite.
In masstone it is a very dark blue/purple and has a rich depth.
In tints it is quite powerful and produces lilac/violet/blues.
Opaque and dense.
Available in 40ml tubes here!
Technical Overview
Pigment - Genuine Indigo
Opacity - Opaque
Binder - Linseed Oil