Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
Color Description
Sap Green was historically made by extracting a dye from buckthorn berries harvested at sites in southern Asia and Persia. The pigment itself was a flavonoid dye. Because the natural plant pigments were not lightfast, the color has been replaced with mixtures of modern pigments that are more permanent.
Winsor & Newton recreates this historic hue from isoindolinone (PY110) and copper phthalocyanine blue (PB15). It is rated permanent (A), and has an ASTM lightfastness rating of I (highest) on a scale of I to V. It is transparent.
This color contains the following pigments:
PY110—Isoindolinone Yellow
Pigment Type
organic synthetic
Chemical Name
isoindolinone yellow
Chemical Formula
n/a
Properties
Isoindolinone Yellow is a high performance pigment of excellent brightness and an average drying time.
Permanence
Isoindolinone Yellow has excellent lightfastness.
Toxicity
Isoindolinone Yellow is not considered toxic.
History
The first isoindoline pigments were patented in 1946, and commercial production of pigments in this group began in the 1960s. Several isoindoline yellow pigments are available.
Alternate Names
Tetrachloroisoindolinone.
PB15—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.
Alternate Names
Bocour Blue, Cyan Blue, Helio Blue, Heliogen Blue, Intense Blue, Monastral Blue, Phthalocyanine Blue, Rembrandt Blue, Thalo Blue, Winsor Blue.
