Sennelier Extra-Fine Artist Acryliques - Burnt Green Earth, 60 ml tube

Pigment Information

This color contains the following pigments:

PBk7-Lamp Black

PG17-Chromium Oxide Green

PR101-Red Iron Oxide

Pigment Name

PBk7-Lamp Black

Pigment Type

inorganic

Chemical Name

carbon

Chemical Formula

C

Properties

Lamp black is a very opaque, heavily staining black pigment that does not have much covering or tinting power. It is typically the most opaque black in watercolor form. Though a very pure black, it tends to muddy slightly in mixtures. Natural sources may be brownish or bluish in tone because of impurities. When used in oil paints, it is one of the slowest drying pigments, and should not be used in underpainting or applied in layers underneath other colors.

Permanence

Lamp Black is very lightfast and absolutely permanent. It is used in all techniques in permanent painting.

Toxicity

<p>Carbon itself is not considered hazardous, however other combustion products that are hazardous are often present as impurities when Lamp Black is produced from natural materials. For this reason, commercial preparations of the pigment should be considered slightly toxic. Avoid skin contact and inhalation. Where such impurities are present, Lamp Black is a possible human carcinogen.</p>

History

Lamp Black is a carbon based black traditionally produced by collecting soot (known as lampblack) from oil lamps. It has been used as a pigment since prehistoric times. It is the black found in Egyptian murals and tomb decorations and was the most popular black for fresco painting until the development of Mars Black.

Pigment Name

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.&nbsp

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.

Pigment Name

PR101-Red Iron Oxide

Pigment Type

earth, synthetic

Chemical Name

iron oxides (synthetic), iron oxide, silica, alumina, lime, and magnesia or hydrated iron oxide

Chemical Formula

Fe2O2 or Fe2O3 x H2O

Properties

Red iron oxide varies in hue and transparency, depending on hydration and slight impurities. Indian Red is a slightly duller, deep brick hue with a bluish undertone. It is very dense and opaque, with excellent tinting strength and covering power. It is dependable when mixing with all other permanent pigments and yields good flesh tints when mixed with Zinc White. It is the synthetic version of PR102, which is a pigment made from earth reds, or natural red iron oxides, and the names applied to PR101 and PR102 often overlap. The synthetic red iron oxides have mostly replaced natural red iron oxides and are brighter, stronger, finer, and more permanent. Indian Red is the highest grade bluish shade. Light Red, English Red, and Venetian Red are yellowish shades. Mars Violet is a dull and subdued bluish or purplish oxide.

Permanence

Red iron oxide is very lightfast with excellent permanence.

Toxicity

Red iron oxide has no significant hazards.

History

Natural red iron oxide comes from the mineral ore hematite, called bloodstone by the ancient Greeks from the word hema, meaning blood. It is one of the oldest pigments, has been used by every major civilization, and was an important mineral for medieval alchemists. It was not widely used in artists' materials until the 17th century and was not produced in large quantities until the 18th century.