A Mars black, it is very clean and warmer than a carbon black, so doesn't suck in quite as much light.
It's warmness is due to the use of synthetic iron oxides, these being the same molecules which give the huge array of earth colours from Yellow to Orange to Brown. It is not as greasy as a carbon black which are basically made from with pigments derived from carbon based oils.
It is a relatively quick drier.
Pigment - Prepared Iron Oxide, PBk 11
Vehicle - Linseed Oil, Consistency - Soft Butter