This color contains the following pigments:
Burnt Sienna is a warm, mid-brown color formed by burning the yellow-brown limonite clay called Raw Sienna. It ranges from semi-opaque to semi-transparent due to the combination of its opaque, red-brown mass tone and its transparent, orangey undertone. It is an excellent mixing complement for blues and greens and creates salmon or peach colored tints when mixed with white. It can be useful for subduing bright colors and does not get chalky in dark mixtures.
Burnt Sienna has good permanence and is considered one of the most versatile of the permanent pigments.
Burnt Sienna has no significant hazards.
Burnt Sienna has been used as a pigment since prehistoric times, but its current name came about during the Renaissance. It comes from the city of Siena, in Italy, and is short for terra di Siena, meaning earth of Siena. Sienna was famous for the mining and production of earth pigments from the Renaissance until World War II. Due to the depletion of clay deposits in Tuscany, Italian siennas now come from other areas, including Sicily and Sardinia.
charred animal bone
carbon + calcium phosphate
C + Ca3(PO4)2 or C × CaPO4
Ivory Black is a cool, semi-transparent blue-black with a slight brownish undertone and average tinting strength. It mixes well with any color, and creates a range of dull greens when mixed with yellow. It has good properties for use in oil, can be slow to dry in oil form, and should never be used in underpainting or frescoing. Ivory Black is denser than Lamp Black.
Ivory Black is very lightfast and has good permanence, though it is considered the least permanent of the major black pigments.
Ivory Black has no significant hazards.
Ivory Black is a carbon based black first named as Elephantium, and described in the 4th century BCE as produced by heating ivory scraps in clay pots to reduce the ivory or bone to charcoal. The deviation in names is because the more expensive varieties of this pigment were made by burning ivory, and the less expensive ones by burning animal bone. In the 19th century, the name Ivory Black was finally permitted to be applied to Carbon Black pigments made from bone. True Ivory Black is rare in modern times due to the protection of ivory, and the synthetic variety produced today was discovered in 1929. Bone Black is produced as an industrial pigment.