D071 Grass Green/Vert d'Herbe - PY3 Hansa Yellow 10G (Organic, monoazo), PG7 Phthalo Green (Organic, Polychlorinated copper (II) phthalocyanine), Titanium White PW6 (inorganic, titanium dioxide)

Series: A

Lightfast: **

Pigment 1: PY3 Hansa Yellow 10G

Hansa Yellows were first made in Germany just before WW1 from a series of synthetic dyestuffs called Pigment Yellow. They were intended to be a synthetic replacement for Cadmium Yellow.

Pigment name: PY3 Hansa Yellow 10G,

Pigment Type: Organic, monoazo

Chemical Name: n/a

Properties: This Hansa yellow is transparent. It has excellent brightness and tinting strength, and its drying time ranges from average to slow.

Hansa Yellow makes more intense tints and cleaner secondaries than Cadmium Yellows, especially when mixed with other organic or modern colours like Phthalo Blue and Green. Because they are more transparent, they have great value as glazing colours.

Permanence: This Hansa Yellow has fair to good permanence, particularly in the lighter shades.

Toxicity: Hansa Yellow has no significant acute hazards, though its chronic risks have not been well studied.

Alternate Names: Acrylamide Yellow, Arylide, Arylide Yellow, Azo, Brilliant Yellow, Monoazo, Monolite Yellow, Permanent Yellow.

Pigment 2: PG7 Phthalo Green

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

Pigment name: PG7 Phthalo Green

Pigment Type: Organic

Chemical Name: Polychlorinated copper (II) phthalocyanine

Properties: Phthalo Green is a transparent, cool, bright, high-intensity colour 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 excellent base colour for mixing a range of bright greens. Phthalo Green is considered a perfect alternative to Viridian because it is intense and mixes well, and can emphasize mineral colours in various tints. However, its tinting strength is very high so that it can overpower other colours. 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.

Alternate Names: Bocour Green, Cyan Green, Intense Green, Monastral Green, Phthalocyanine Green, Rembrandt Green, Thalo Green, Winsor Green.

Pigment 3: Titanium White PW6

Titanium is the ninth most abundant element in the Earth's crust; however, mineral deposits that are economical to mine are less common. Titanium dioxide was first discovered in 1821, although it could not be mass-produced until 1919. Widespread use of the pigment began in the 1940s. Since that time, it has become the most commonly used white pigment. The name comes from the Latin word Titan, the name for the elder brother of Kronos and ancestor of the Titans, and the Greek word tito, meaning day or sun.

Pigment Name: Titanium White PW6

Pigment Type: Inorganic

Chemical Name: Titanium dioxide

Properties: Titanium White is the most brilliant of the white pigments. It is considered an all-purpose oil colour useful in all techniques and the best all-around white. Its masstone is neither warm nor cool, placing it somewhere between Lead White and Zinc White. It is less prone to cracking and yellowing than Lead White, but it still yellows easily. Titanium White dries slowly in oil form, more slowly than Lead White but more quickly than Zinc White. It is opaque in oil and acrylic forms and semi-opaque in watercolour. This pigment has good chemical stability, and its tinting strength is superior to both Lead White and Zinc White.

Permanence: Titanium White has excellent permanence and lightfastness.

Toxicity: Titanium dioxide is highly stable and is regarded as completely non-toxic. Animal studies do not indicate that it is absorbed biologically, even after long periods of exposure. The primary safety concern is with inhalation of fine pigment dust particles. If inhaled in large amounts over the course of several years, Titanium White may cause a benign pneumoconiosis that is visible on x-rays. The National Institute of Occupational Safety and Health (NIOSH) considers fine titanium dioxide particles, if inhaled, to be a human carcinogen. The primary concern for artists is to avoid exposure to fine particulate dust from raw pigments.

Alternate Names: None.