This color contains the following pigments:
PG17-Chromium Oxide Green
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.
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.
Phthalo Blues have no significant hazards, although those made before 1982 contained some PCBs (polychlorinated biphenyls).
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.
PG17-Chromium Oxide Green
Chromium Oxide Green is a dull, dense, willow or pale green color that is completely opaque. It has an average drying time and a low tinting strength. It is fairly flexible in oil form and is suitable for all purposes and mediums. This pigment is less versatile in mixtures than Viridian and Phthalocyanine Green, but mixes well with other colors without overpowering them.
Chromium Oxide Green has excellent permanence, even at high temperatures.
Chromium Oxide Green is slightly toxic. Evidence of Chromium(III) carcinogenicity is inconclusive. Chromium(III) salts appear in greenish pigments such as PG17. Chromium(VI) salts, which appear in yellowish pigments, have been proven to cause cancer.
Louis-Nicolas Vauquelin discovered the element chromium in lead chromate in 1797. It began to be used as an enamel and ceramic color in 1809, but it had limited use as a pigment until 1862, because of its cost. It is the most commonly used green for military camouflage because it appears the same shade as living foliage under infrared light.