Rembrandt Soft Pastel - Permanent Yellow Green 633.9, Full Stick

Pigment Information

This color contains the following pigments:

PY83-Diarylide Yellow 83

PG36-Phthalo Green

PY184-Bismuth Yellow

Pigment Name

PY83-Diarylide Yellow 83

Pigment Type

organic, disazo

Chemical Formula

C36H32Cl4N6O8

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’ color. 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.

History

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

PG36-Phthalo Green

Pigment Type

organic

Chemical Name

polybromopolychlorinated copper(II) phthalocyanine

Chemical Formula

C32H3Cl13CuN8 to C32HCl15CuN8 or C32H16CuN8Cl15 (PG7) or C32Br6Cl10CuN8 (PG36)

Properties

Phthalo Green is a transparent, cool, bright, high intensity color 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.  Pigment PG36 differs from PG7 in that a portion of the chlorine atoms are replaced with bromine atoms, which are reactively similar, but cause a yellow shift that is especially noticeable in mixtures. Phthalo Green has similar pigment properties and permanence to Phthalo Blue. It is slow drying and an excellent base color 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 colors in various tints. However, its tinting strength is very high, so it can overpower other colors.  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.

History

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

Pigment Name

PY184-Bismuth Yellow

Pigment Type

inorganic

Chemical Name

bismuth orthovanadate or bismuth vanadium oxide

Chemical Formula

BiVO4

Properties

Bismuth Yellow is an intense, light value, semi-opaque yellow pigment with good tinting strength.

Permanence

Bismuth Yellow has excellent lightfastness.

Toxicity

Bismuth orthovanadate is harmful if swallowed. It is irritating to the eyes, respiratory system, and skin. Exposure may cause conjunctivitis, rhinitis, and reversible irritation of the respiratory tract. More severe cases may cause bronchitis, bronchospas

History

Bismuth orthovanadate occurs naturally in several minerals. Although it was synthesized in the 1920s, it was not developed as a commercial pigment until the 1970s.