Sennelier Watercolour S3 Viridian Green (837)

Viridian Green (837) Phthalo Green is a transparent, cool, bright, high-intensity colour. An excellent base colour for mixing a range of bright greens. Viridian is the standard green and is stable, robust, and cold with an emerald green undertone. It has a transparent hue, good tinting strength, and dark masstone that can be almost black at full strength. 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.

Pigment Name: Phthalo Green PG7

Phthalo Green is a transparent, cool, bright, high-intensity colour used in oil and acrylics. It comes from a Phthalocyanine Blue pigment where most hydrogen atoms have been replaced with chlorine, forming highly stable molecules. It has pigment properties and permanence similar to Phthalo Blue. It is slow drying and an excellent base colour for mixing a range of bright greens. Phthalo Green is considered a good alternative to Viridian because it is intense, mixes well, and can be used to emphasize mineral colours in various tints. However, its tinting strength is very high, so that it can overpower other colours. This pigment most closely resembles the discontinued and toxic Verdigris.

Chemical Name: polychlorinated copper(II) phthalocyanine.

Permanence: Phthalo Greens are completely lightfast and resistant to alkali, acids, solvents, heat, and ultraviolet radiation. Due to their stability, they are currently used in inks, coatings, and many plastics and are considered a standard pigment in printing ink and the packaging industry.

Toxicity: Phthalo Green has no significant hazards, but it contained PCBs (polychlorinated biphenyls) until 1982.

History: This bright blue-green was developed in 1935 and has been used since 1938.

Alternate Names: Bocour Green, Cyan Green, Intense Green, Monastral Green, Phthalocyanine Green, Rembrandt Green, Thalo Green, Winsor Green.

Pigment Name: Viridian PG18

Viridian is the standard green and is stable, robust, 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. Chemical Name: chromium(III)-oxide dehydrate.

Chemical Name: chromium(III)-oxide dehydrate.

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

Toxicity: Viridian is slightly toxic.

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

Alternate Names: Emerald Chromium Oxide, Emeraude Green, French Veronese Green, Guignet’s Green, Pannetier's Green, Permanent Green, Smaragd Green, Transparent Oxide of Chromium, Vert Emeraude. Casali's Green and Mittler's Green are varieties of Viridian. Viridian has historically been sold under Emerald Green, but they are currently considered and marketed as two different pigments.