Gamblin 1980 Oils -andnbsp;PB36-Cerulean Blue (Oxide of cobalt(II) stannate, chromium and aluminum); PB15:2-Phthalo Blue (Copper phthalocyanine)

Cerulean Blue: Mixed metal oxide from the early 19th century with an important place on the mineral palette because blues rarely shift to the cool, green side, like this one. It is muted in its tint, so it is most valuable as a pure hue.

It quickly dries and retains its colour well, better than any other blue, in oil paint form. It has limited hiding power, is semi-opaque, and is easy to control. Its tinting capacity is low, so it can become lost when mixing.

Pigmentandnbsp;Composition and Permanence:andnbsp;

Pigment Name: PB35-Cerulean Blue

Pigment Type: inorganic

Properties

Cerulean Blue is the standard cool blue, considered the traditional counterpart to Ultramarine, and is often used for painting atmospheric shades.

It quickly dries and retains its colour well, better than any other blue, in oil paint form. However, it tends to granulate or become chalky in watercolours.

It has limited hiding power, is semi-opaque, and is easy to control. Its tinting capacity is low, so it can become lost when mixing.

Permanence

Cerulean Blue has excellent permanence. It is very stable and lightfast.

Toxicity

Cerulean Blue is moderately toxic if inhaled or ingested and slightly toxic if it comes into contact with skin.

History

The name Cerulean Blue comes from the Latin word caelum, meaning sky. This pigment was discovered in 1805 by Andreas Hopfner. Still, it was not widely available until introduced by Messrs. G. Rowney andamp; Co. in England under the name coeruleum in 1860 for use in aquarelle and oil painting. It was produced by the action of heat on cobalt oxide and other metallic bases.

andnbsp;

2ndandnbsp;Pigmentandnbsp;Composition and Permanence:andnbsp;

Pigment Name: PB15:2-Phthalo Blue

Pigment Type: Organic

Properties

Phthalo Blue PB15:2 is a structural variant of Phthalo Blue PB15 that produces more greenish tones.

Permanence

Phthalo Blues are completely lightfast, stable, and permanent for all paint uses. Due to their stability, they are currently used in inks, coatings, and many plastics 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 colour was observed in a kettle where a dye was made from a British dyestuff plant. The demand for such a pigment came from commercial printers who wanted cyan to replace Prussian Blue.