Description
This is the real deal from India, not an approximation produced by mixing several modern pigments, it is genuine, produced from the plant Indigofera tinctoria (shown opposite).
Indigo has a long, long history and contains some unpleasant moments from the era of the British Empire where slave labour was used in its intensive and 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 above.
In masstone it is a very dark blue/purple and has a rich depth which seems to be visible in a lot of these historic paints. In tints it is quite powerful and produces lilac/violet/blues.
Technical Overview
Pigment - Genuine Indigo
Opacity - Semi-Opaque
Binder - Linseed Oil
Munsell - Hue 7.5 PB - Value 3 - Chroma 1