Description Colour Index PBr 6 Drying Speed Very Fast Opacity Covering and Tint Power Semi-Transparent Lightfastness Excellent Oil Content Average, Linseed Toxic No Conforms To ASTM D-4236 ƒ‚‚ A synthetic iron oxide. I decided to make this variant shade of Burnt Umber as a result of my observations of 16 -17th paintings which suggested that this pigment had lighter and redder characteristics than those it assumed when manufactured in held in animal bladders. Raw Umber is calcinated to make the pigment, and the extent of Manganese Dioxide mixed with the Iron Oxide determines the range of undertones; my formulation is much warmer than is usual.
