Rembrandt Artists' Oil Color - Indigo, 40 ml tube

Pigment Information

This color contains the following pigments:

PB15:6-Phthalo Blue

PB29-Ultramarine [Blue]

PBk9-Ivory Black

Pigment Name

PB15:6-Phthalo Blue

Pigment Type

organic

Chemical Name

epsilon copper phthalocyanine

Chemical Formula

C32H16CuN8

Properties

Phthalo Blue PB15:6 is a structural variant of Phthalo Blue PB15 that produces more yellowish tones.

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.

Pigment Name

PB29-Ultramarine [Blue]

Pigment Type

inorganic

Chemical Name

complex silicate of sodium and aluminum with sulfur

Chemical Formula

Na8-10Al6Si6O24S2-4 or Na6-8Al6Si6O24S2-4

Properties

Ultramarine is the standard warm blue, a brilliant blue pigment that has the most purple and least green in its undertone. It has a moderate to high tinting strength and a beautiful transparency. Synthetic Ultramarine is not as vivid a blue as natural Ultramarine. Ultramarine dries slowly in oil and tends to produce clean, though granular, washes in watercolor. French Ultramarine mixes well with Alizarin colors in oil and watercolor form to create a range of purples and violets. It can dull when mixed with white in acrylic form, but mixes well with other colors. The shade varies based on manufacturer. Considered a great color for glazes, it is not suitable for frescoing.

Permanence

Ultramarine has excellent permanence, although synthetic Ultramarine is not as permanent as natural Ultramarine. It may discolor if exposed to acid because of its sulfuric content.

Toxicity

Ultramarine has no significant hazards.

History

The name for this pigment comes from the Middle Latin ultra, meaning beyond, and mare, meaning sea, because it was imported from Asia to Europe by sea. It is a prominent component of lapis lazuli and was used on Asian temples starting in the 6th century. It was one of the most expensive pigments in 16th century Europe, worth twice its weight in gold, and so was used sparingly and when commissions were larger. Ultramarine is currently imitated by a process invented in France in 1826 by Jean Baptiste Guimet, making blue affordable to artists and extending the range of colors on their palettes.

Pigment Name

PBk9-Ivory Black

Pigment Type

charred animal bone

Chemical Name

carbon + calcium phosphate

Chemical Formula

C + Ca3(PO4)2 or C x CaPO4

Properties

Ivory Black is a cool, semi-transparent blue-black with a slight brownish undertone and average tinting strength. It mixes well with any color, and creates a range of dull greens when mixed with yellow. It has good properties for use in oil, can be slow to dry in oil form, and should never be used in underpainting or frescoing. Ivory Black is denser than Lamp Black.

Permanence

Ivory Black is very lightfast and has good permanence, though it is considered the least permanent of the major black pigments.

Toxicity

Ivory Black has no significant hazards.

History

Ivory Black is a carbon based black first named as Elephantium, and described in the 4th century BCE as produced by heating ivory scraps in clay pots to reduce the ivory or bone to charcoal. The deviation in names is because the more expensive varieties of this pigment were made by burning ivory, and the less expensive ones by burning animal bone. In the 19th century, the name Ivory Black was finally permitted to be applied to Carbon Black pigments made from bone. True Ivory Black is rare in modern times due to the protection of ivory, and the synthetic variety produced today was discovered in 1929. Bone Black is produced as an industrial pigment.