Winsor & Newton Professional Watercolor - Olive Green, 14 ml Tube

Pigment Information

This color contains the following pigments:

PB15:6-Phthalo Blue

PY65-Hansa Yellow

PR101-Red Iron Oxide

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

PY65-Hansa Yellow

Pigment Type

monoazo

Chemical Formula

C18H18N4O6

Properties

This Hansa Yellow ranges from reddish yellow to greenish yellow with temperature shifts from cool to warm hues. It has good tinting strength and average to slow drying time.

Permanence

This Hansa Yellow has excellent lightfastness, particularly in the darker shades.

Toxicity

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

History

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

PR101-Red Iron Oxide

Pigment Type

earth, synthetic

Chemical Name

iron oxides (synthetic), iron oxide, silica, alumina, lime, and magnesia or hydrated iron oxide

Chemical Formula

Fe2O2 or Fe2O3 x H2O

Properties

Red iron oxide varies in hue and transparency, depending on hydration and slight impurities. Indian Red is a slightly duller, deep brick hue with a bluish undertone. It is very dense and opaque, with excellent tinting strength and covering power. It is dependable when mixing with all other permanent pigments and yields good flesh tints when mixed with Zinc White. It is the synthetic version of PR102, which is a pigment made from earth reds, or natural red iron oxides, and the names applied to PR101 and PR102 often overlap. The synthetic red iron oxides have mostly replaced natural red iron oxides and are brighter, stronger, finer, and more permanent. Indian Red is the highest grade bluish shade. Light Red, English Red, and Venetian Red are yellowish shades. Mars Violet is a dull and subdued bluish or purplish oxide.

Permanence

Red iron oxide is very lightfast with excellent permanence.

Toxicity

Red iron oxide has no significant hazards.

History

Natural red iron oxide comes from the mineral ore hematite, called bloodstone by the ancient Greeks from the word hema, meaning blood. It is one of the oldest pigments, has been used by every major civilization, and was an important mineral for medieval alchemists. It was not widely used in artists' materials until the 17th century and was not produced in large quantities until the 18th century.