Grumbacher Academy Watercolor - Green Earth Hue, 7.5 ml tube

Pigment Information

This color contains the following pigments:

PG18-Viridian

PBr7-Raw Umber

Pigment Name

PG18-Viridian

Pigment Type

inorganic

Chemical Name

chromium(III)-oxide dehydrate

Chemical Formula

Cr2O3 • 2 H2O or Cr2(OH3)

Properties

Viridian is the standard green and is stable, powerful, and cold with an emerald green undertone. It has a transparent hue, good tinting strength, a dark masstone that can be almost black at full strength, and a slow drying time in oil form. Viridian is commonly replaced by the darker, more saturated, and staining Phthalo Greens, but its properties make it a necessary part of the palette of an experienced landscape painter.

Permanence

Viridian has excellent permanence, except in high-temperature work, and is highly valued as a glazing color.

Toxicity

Viridian is slightly toxic.

History

Viridian’s name comes from the Latin viridis, meaning green. The process for manufacturing Viridian, or Transparent Oxide of Chromium, was patented by Guignet in Paris in 1859. However, it had actually been discovered by Pannetier and Binet in 1838. Viridian replaced Verdigris, which was reactive and unstable, and Emerald Green, which was a poisonous copper aceto-arsenite used as a rat poison in the sewers of Paris.

Pigment Name

PBr7-Raw Umber

Pigment Type

earth

Chemical Name

hydrated iron oxide

Chemical Formula

α-FeO3+(OH) or Fe2O3 × MnO2

Properties

Raw Umber is a cool, transparent brown ranging from yellowish brown to greenish brown. It has surprisingly good tinting strength, a high level of opacity, mixes well with greens, and is quick drying in oil form. It has excellent color properties and can create a variety of subtle, clear tints when mixed with white. It grays when mixed with blue and white. Raw Umber can tend towards chalkiness in dark mixes in oil form.

Permanence

Raw Umber has excellent permanence.

Toxicity

Raw Umber itself is considered non-toxic. If contaminated by manganese compounds, it may be highly toxic if inhaled and moderately toxic if ingested.

History

This pigment gets its name from the Latin word umbra, meaning shadow or shade. Its full name is listed as terra di ombra, meaning earth of shadow/shade, due to its original extraction from the area of Umbria, Italy. It has been used as a pigment since prehistoric times. Currently, the finest umber comes from Cyprus.