Grumbacher Academy Watercolor - Sap Green, 7.5 ml tube

Pigment Information

This color contains the following pigments:

PB15:4-Phthalo Blue

PO48-Quinacridone Gold

PG7-Phthalo Green

PY150-Nickel Azo Yellow

Pigment Name

PB15:4-Phthalo Blue

Pigment Type

organic

Chemical Name

copper phthalocyanine

Chemical Formula

C32H16CuN8

Properties

Phthalo Blues are pure and clean primary blues with superior covering power. They have a very high tinting strength and tend to overwhelm other pigments, but if color strength can be controlled, they make predictable mixed colors. In oil form, blues are very deep and slow drying. When mixed with other colors or if chlorine is added, Phthalo Blue quickly tends towards green. When using alone, mix with some white, as Phthalo Blue can be semi-transparent and almost black on its own. It is among the most compatible of modern colors with mineral colors and is considered more reliable than Prussian Blue, while sharing the same physical and color properties. Phthalo Blue is a good color for glazing.

Permanence

Phthalo Blues are completely lightfast and stable and are permanent for all paint uses. 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 Blues have no significant hazards, although those made before 1982 contained some PCBs (polychlorinated biphenyls).

History

Developed by chemists using the trade name Monastral Blue, the organic blue dyestuff now known as Phthalo Blue was presented as a pigment in November 1935 in London. Its discovery was accidental. The dark color was observed in a kettle where a dye was being made from a British dyestuff plant. The demand for such a pigment came from commercial printers who wanted a cyan to replace Prussian Blue.

Pigment Name

PO48-Quinacridone Gold

Pigment Type

organic, quinacridone

Chemical Formula

C20H12N2O2 or C20H10N2O4

Properties

Quinacridone Gold is a high performance pigment. It lacks brightness and cleanliness in tints, and it may disperse unevenly. It has an average drying time. Quinacridone pigments have relatively low tinting strength in general. For this reason, quinacridone colors are often expensive, because more pigment is required in the formulation.

Permanence

Quinacridone Gold has excellent lightfastness and is considered the most lightfast pigment in its shade range.

Toxicity

Quinacridone gold is not considered toxic. Overexposure to quinacridone pigments may cause skin irritation. Quinicridone pigments contain a compound found to be a skin, eye, and respiratory irritant.

History

Although quinacridone compounds became known in the late 19th century, methods of manufacturing so as to make them practical for use as commercial pigments did not begin until the 1950s. Quinacridone pigments were first developed as coatings for the automotive industry, but were quickly adopted by artists.

Pigment Name

PG7-Phthalo Green

Pigment Type

organic

Chemical Name

polychlorinated 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. It 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

PY150-Nickel Azo Yellow

Pigment Type

inorganic

Chemical Name

nickel azomethine yellow

Chemical Formula

C30H18Cl2N6NiO4

Properties

Nickel Azo Yellow is a transparent, moderately staining yellow pigment with high tinting strength. It is considered a good color match in botanical and landscape painting for natural gamboge (NY24), a historic yellow pigment with fair to poor lightfastness.

Permanence

Nickel azomethine yellow has excellent lightfastness.

Toxicity

Nickel azo yellow pigment is mildly toxic, and is often labeled as hazardous. Avoid respiratory and skin exposure to pigment dust. It should be disposed of properly with other hazardous wastes, not washed down the sink.

History

Nickel azomethine yellow has been developed as an artist pigment becasue it is a close match for gamboge, a historic yellow.