Unbleached Titanium Dioxide, the same pigment which is bleached to create Titanium White. In this it's more natural state it contains small amounts of Iron Oxide, the substance responsible for the amazing colour diversity of Ochres, Umbers, etc.
This leads it to have a very subtle 'buff' colour and due to it being relatively unprocessed the microscopic irregular particle size is maintained which enables the pigment to bounce more light around and appear to have more depth than a highly refined pigment.
When used in colour mixing this paint can have some very beautiful effects, it takes down the chroma very gently, which can be tricky with some colours using just complementaries.
This is an excellent paint and experimenting with it can lead to some very gentle colour shifts.
Excellent when used with earths for flesh tones.
Pigment - Titanium Dioxide, PW6.1
Vehicle - Linseed Oil, Consistency - Dense