Grumbacher Pre-Tested Artists' Oil Color - Brown Pink, 1.25 oz tube

Pigment Information

This color contains the following pigments:

PBr7-Raw Sienna

PY150-Nickel Azo Yellow

Pigment Name

PBr7-Raw Sienna

Pigment Type

earth

Chemical Name

hydrated iron oxide

Chemical Formula

α-FeO3+(OH) or Fe2O3

Properties

Raw Sienna is a moderately dull deep earth yellow with medium tinting strength and excellent transparency. It is one of the basic permanent artists' pigments and is made from a form of limonite clay whose yellow-brown color results from ferric oxides. Raw Sienna is preferable to Yellow Ochre for creating flesh tones, due to its higher subtlety of color when mixed with white. It creates a bright Ochre when mixed with Cadmium Yellow and creates greens and grays when mixed with Ultramarine. Raw Sienna dries quickly.

Permanence

Raw Sienna has good permanence.

Toxicity

Raw Sienna has no significant hazards.

History

Raw Sienna has been used as a pigment since prehistoric times, although 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.

Pigment Name

PY150-Nickel Azo Yellow

Pigment Type

inorganic

Chemical Name

nickel azomethine yellow

Chemical Formula

C30H18Cl2N6NiO4

Properties

Nickel Azo Yellow is a transparent, moderately staining yellow pigment with high tinting strength. It is considered a good color match in botanical and landscape painting for natural gamboge (NY24), a historic yellow pigment with fair to poor lightfastness.

Permanence

Nickel azomethine yellow has excellent lightfastness.

Toxicity

Nickel azo yellow pigment is mildly toxic, and is often labeled as hazardous. Avoid respiratory and skin exposure to pigment dust. It should be disposed of properly with other hazardous wastes, not washed down the sink.

History

Nickel azomethine yellow has been developed as an artist pigment becasue it is a close match for gamboge, a historic yellow.