Sennelier Artists' Oil Stick - Indigo Blue

Pigment Information

This color contains the following pigments:

PBk1-Aniline Black

PB15:3-Phthalo Blue

Pigment Name

PBk1-Aniline Black

Pigment Type

organic, azine

Chemical Formula

Properties

Analine black was the first black dye used to color cotton.

Permanence

As a clothing dye, it has been reported to have excellent lightfastness.

Toxicity

Testing of analine black dye on rabbits has shown that it is not an skin or eye irritant.

History

Analine Black was discovered by Lightfoot in 1863. It has been used ever since as a black dye for coloring cotton.

Pigment Name

PB15:3-Phthalo Blue

Pigment Type

organic

Chemical Name

beta copper phthalocyanine

Chemical Formula

C32H16CuN8

Properties

Phthalo Blue PB15:3 is a structural variant of Phthalo Blue PB15 that produces more greenish 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.