Mars Black is an opaque black with a strong and cool masstone, a slightly warm tint, and a warm brown undertone. It is not as black as Ivory Black, but it dries more quickly and has three times the tinting strength. Mars Black is normally the only black available in acrylic form and that is safe to over paint. It can be used in all media without reservation and is widely used as an alternative to Lamp Black and Ivory Black.
Mars Black is very lightfast with excellent permanence.
Mars Black has no significant hazards and is the only major black pigment considered non-toxic.
The word Mars refers to the Roman god of iron and war. Mars Black was developed in the early 20th century from inorganic, synthetic iron oxide.
organic, vat dyes
complex, insoluble anthraquinone
Indanthrene Blue is a clear, clean, deep blue organic pigment. It has moderate to high tinting strength and is not as overpowering as Phthalo Blue. Hansa Yellow Deep, Benzimidazolone Orange, and Raw Umber are its best mixing complements.
Indanthrene Blue is permanent with excellent lightfastness in both masstone and tints.
Indanthrene Blue varies in its acute toxicity, though toxicity is generally slight.
Indanthrene Blue is the oldest vat dye, discovered and patented in 1901 by Rene Bohn. It is considered the first anthraquinone vat dye, a group of dyes characterized by excellent lightfastness. The pigment originates from this dye.
Zinc White is the coolest white, and it has a cold, clean masstone and a slightly bluish tint. It has less hiding power and is more transparent than other whites. It dries slowly and is good for painting wet into wet and for glazing and scumbling. Zinc White is neither as opaque nor as heavy as Lead White, its covering power is not as good, and it takes much longer to dry. However, it does not blacken when exposed to sulfur in the air as Lead White does. It is very valuable for making tints with other colors. Unmixed Zinc White dries to a brittle and dry paint film that may crack over the years, so it is not good for frescoing. It is more transparent in acrylic form than Titanium White and is the most commonly used white with gouache. Chinese White is a version of Zinc White appropriate for opaque watercolor techniques.
Zinc White has great permanence and lightfastness.
Zinc White is moderately toxic if ingested and slightly toxic if inhaled.
Though historians are divided on who first isolated the element zinc, they agree that it was first suggested as a white pigment in 1782. Zinc White was accepted as a watercolor in 1834 and was called Chinese White due to the popularity of oriental porcelain in Europe at the time. Ten years later, a suitable oil form was produced. By the early 20th century, it had improved to the point where it was an acceptable alternative to Flake White.