This pigment was invented in 1901 as an extremely lightfast dye, Indanthrone is now used in a multitude of applications due to it's great stability and depth of colour.
In masstone a very dark blue, transparent which is generally preferable in colour mixing, enabling the light to move through the paint giving more 'glow'.
A medium/strong tinter providing a wide range of tints with white added, it makes slightly green leaning blue tints reminescent of Cerulean blue.
It is like a gentler Phthalo Blue, and I can see a real place on most palettes for this as a 'cool' blue, although having a similar hue to Phthalo blue it is much easier to control in mixes.
It would make a great chromatic black when mixed with a transparent complementary colour and from that you could derive some really good chromatic greys.
Pigment - PB60
Vehicle - Linseed Oil
Opacity - Transparent
Tint Power - Medium to High