Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
This color contains the following pigments:
PBr7—Burnt Sienna
Pigment Type
earth
Chemical Name
iron oxides
Chemical Formula
Fe2O3
Properties
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.
Permanence
Burnt Sienna has good permanence and is considered one of the most versatile of the permanent pigments.
Toxicity
Burnt Sienna has no significant hazards.
History
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.
Alternate Names
Caput Mortuum, Italian Earth, Natural Brown Iron Oxide, Sienna, Spanish Red, Vandyke Brown.
PG17—Chromium Oxide Green
Pigment Type
inorganic
Chemical Name
chromium oxide
Chemical Formula
Cr2O3
Properties
Chromium Oxide Green is a dull, dense, willow or pale green color that is completely opaque. It has an average drying time and a low tinting strength. It is fairly flexible in oil form and is suitable for all purposes and mediums. This pigment is less versatile in mixtures than Viridian and Phthalocyanine Green, but mixes well with other colors without overpowering them.
Permanence
Chromium Oxide Green has excellent permanence, even at high temperatures.
Toxicity
Chromium Oxide Green is slightly toxic. Evidence of Chromium(III) carcinogenicity is inconclusive. Chromium(III) salts appear in greenish pigments such as PG17. Chromium(VI) salts, which appear in yellowish pigments, have been proven to cause cancer.
History
Louis-Nicolas Vauquelin discovered the element chromium in lead chromate in 1797. It began to be used as an enamel and ceramic color in 1809, but it had limited use as a pigment until 1862, because of its cost. It is the most commonly used green for military camouflage because it appears the same shade as living foliage under infrared light.
Alternate Names
Chrome Oxide Green, Olive Green, Permanent Green. Varieties of Chromium Oxide Green include Arnaudon's Green, Dingler's Green, Plessy's Green, and Schnitzer's Green.
