Winsor & Newton Cotman Watercolor Half Pan - Sap Green

Pigment Information

This color contains the following pigments:

PG36-Phthalo Green

PR101-Mars Orange

PY139-Isoindolinone Yellow

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

PR101-Mars Orange

Pigment Type

Chemical Name

iron oxides

Chemical Formula

Fe2O2 or Fe2O3 • H2O

Properties

Mars Orange is a bright, extremely light red and appears almost pinkish when contrasted with darker colors. It has incredible tinting strength and opacity. The synthetic form of Mars Orange is made from iron oxides and is cleaner, brighter, and denser than its ochre-based counterparts.

Permanence

Mars Orange has good permanence and lightfastness.

Toxicity

Mars Orange has no significant hazards.

History

The word Mars refers to the Roman god of iron and war. Mars Orange has been manufactured as a pigment since the 17th century.

Pigment Name

PY139-Isoindolinone Yellow

Pigment Type

organic, azomethine

Chemical Formula

C16H19N5O6

Properties

Isoindolinone Yellow is a new-generation organic pigment that has a very high tinting strength and average drying time.

Permanence

Isoindolinone Yellow has excellent lightfastness.

Toxicity

Isoindolinone Yellow is not considered toxic.

History

The first isoindolinone pigments were patented in 1946, and commercial production of pigments in this group began in the 1960s. Several isoindolinone yellow pigments are available.