Sennelier Extra-Fine Artist Acryliques - Raw Umber, 200 ml tube

Pigment Information

This color contains the following pigments:

PBk11-Mars Black

PY74-Hansa Yellow

PY42-Yellow Ochre

PR101-Red Iron Oxide

Pigment Name

PBk11-Mars Black

Pigment Type

earth

Chemical Name

iron oxides

Chemical Formula

FeO or Fe2O3

Properties

Mars Black is an opaque black with a strong and cool masstone, a slightly warm tint, and a warm brown undertone. It is not as black as Ivory Black, but it dries more quickly and has three times the tinting strength. Mars Black is normally the only black available in acrylic form and that is safe to over paint. It can be used in all media without reservation and is widely used as an alternative to Lamp Black and Ivory Black.

Permanence

Mars Black is very lightfast with excellent permanence.

Toxicity

Mars Black has no significant hazards and is the only major black pigment considered non-toxic.

History

The word Mars refers to the Roman god of iron and war. Mars Black was developed in the early 20th century from inorganic, synthetic iron oxide.

Pigment Name

PY74-Hansa Yellow

Pigment Type

monoazo

Chemical Formula

C18H18N4O6

Properties

Pigment PY74 is one of the most commercially important pigments of the Hansa Yellow group, considered superior to many others in its class based on both tinting strength and lightfastness. Several PY74 grades with different particle sizes are available. Grades with finer particle size are more brilliant and transparent. Pigment PY74 ranges from reddish yellow to greenish yellow, with temperature shifts from cool to warm hues. It has high tinting strength and average to slow drying time.

Permanence

This Hansa Yellow has better lightfastness that other yellow monoazo pigments, particularly in the darker shades.

Toxicity

Hansa Yellow has no significant acute hazards, though its chronic hazards have not been well studied.

History

Hansa Yellows were first made in Germany just before WW1 from a series of synthetic dyestuffs called Pigment Yellow. They were intended to be a synthetic replacement for Cadmium Yellow.

Pigment Name

PY42-Yellow Ochre

Pigment Type

Chemical Name

iron(III)-oxide, hydrated

Chemical Formula

Fe2O3 • H2O

Properties

Yellow Ochre provides artists with earthtones from cream to brown. It has good hiding power, produces a quick drying paint, and can be safely mixed with other pigments. Its transparency varies widely from opaque shades to more transparent ones, which are valued for their use as glazes. If gypsum is present, Yellow Ochre is not suitable for frescoing. (See Brown Ochre, PY43.) PY42 is made from synthetic iron oxides. PY43 is made from natural iron oxide.

Permanence

Yellow Ochre has excellent permanence because ochres are some of the most permanent pigments available.

Toxicity

Yellow Ochre is non-toxic unless it contains manganese.

History

Ochre comes from the Greek word ochros, meaning pale yellow. It was one of the first pigments to be used by human beings, and evidence of its use has been found at 300,000 year old sites in France and the former Czechoslovakia.

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 • 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.