D063 D763 Deep Green/Vert Foncé - PY83 Diarylide Yellow 83 (Organic, disazo), PG7 Phthalo Green (Organic, Polychlorinated copper (II) phthalocyanine)

Series: A

Lightfast: **

Pigment 1: PY83 Diarylide Yellow 83

Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.

Pigment name: PY83 Diarylide Yellow 83

Pigment Type: Organic, disazo

Chemical Name: n/a

Properties: Diarylide Yellow is a semi-opaque, moderately staining, intense deep reddish yellow pigment with good tinting strength.

Permanence: Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists’ colour. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.

Toxicity: Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.

Alternate Names: Benzidine Yellow, Diazo Yellow.

Pigment 2: PG7 Phthalo Green

This bright blue-green was developed in 1935 and has been in use since 1938.

Pigment name: PG7 Phthalo Green

Pigment Type: Organic

Chemical Name: Polychlorinated copper (II) phthalocyanine

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

Permanence: Phthalo Greens are completely lightfast and resistant to alkali, acids, solvents, heat, and ultraviolet radiation. They are currently used in inks, coatings, and many plastics due to their stability 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.

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