Blockx Artist Oil Color - Mixed Green Deep, 200 ml tube

Pigment Information

This color contains the following pigments:

PY40-Cobalt Yellow

PG18-Viridian

Pigment Name

PY40-Cobalt Yellow

Pigment Type

inorganic

Chemical Name

cobalt potassium nitrite

Chemical Formula

K3[Co(NO2)6]·H2O or CoK3N6O12

Properties

Cobalt Yellow is an expensive, transparent, very pure yellow with only fair hiding power. It is reliable in watercolor and makes particularly good tints. However, it must be carefully manufactured in oil form, or it can brown. Cobalt Yellow is known for good mixing quality with all other pigments, and it is useful in glazes and for tinting.

Permanence

Cobalt Yellow has good permanence and lightfastness, and it can withstand strong sunlight.

Toxicity

Cobalt Yellow is highly toxic by inhalation or ingestion. The ingestion of this pigment has caused cyanosis (low oxygen levels in the blood) due to methemoglobinemia.

History

Cobalt comes from the Middle High German word kobolt, an underground goblin, because miners thought cobalt harmed silver ores. The discovery of the potassium and cobalt compound used to make Cobalt Yellow is credited to N.W. Fischer in Breslau in 1848. It was not introduced as an artists’ pigment until 4 years later, by Saint-Evre in Paris. During the previous century, it was considered the only color that could reasonably replace Indian Yellow.

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.