Grumbacher Academy Oil Color - Cadmium Red Light Hue, 37 ml tube

Pigment Information

This color contains the following pigments:

PR188 -Naphthol Red

PR170-Naphthol Red

PY65-Hansa Yellow

PR166-Cromophtal Scarlet

Pigment Name

PR188 -Naphthol Red

Pigment Type

organic monoazo

Chemical Formula

C33H24Cl2N2O6

Properties

This Naphthol Red is yellowish, with a high tinting strength and average drying time. It produces warmer shades and tints.

Permanence

This Naphthol Red has excellent lightfastness, though it is generally not considered adequate for exterior use.

Toxicity

Naphthol Reds are not considered toxic. They may cause eye, skin, or respiratory irritation. Contact with dry pigment should be avoided.

History

Naphthol pigments are actually dyes that are "laked" to form pigments. First developed by the German chemical company Hoechst A.G. before World War I, their use in artist paints began in the 1920s.

Pigment Name

PR170-Naphthol Red

Pigment Type

organic, naphthol AS

Chemical Formula

C26H22N4O4

Properties

Pigment PR170 is a bright deep red with bluish undertones. It has an average drying time. It has two crystaline forms that differ significantly in opacity. The more transparent form (F5RK) tends to be more bluish and is less lightfast.

Permanence

The lightfastness and weatherfastness of Pigment PR170 varies, depending on the application and the crystaline form. The opaque form (F3RK) has very good lightfastness, and is more weather resistant. The transparent form (F5RK) has lightfastness that is considered acceptable in pure applications, but it fades more in tints. Neither form is considered suitable for exterior use.

Toxicity

Naphthol Reds are not considered toxic. They may cause eye, skin, or respiratory irritation. Contact with dry pigment should be avoided.

History

Naphthol pigments are actually dyes that are "laked" to form pigments. First developed by the German chemical company Hoechst A.G. before World War I, their use in artist paints began in the 1920s. Pigment Red PR170 is a Naphthol AS pigment, chemically related to the diarylide yellow pigments. The Naphthol AS pigments comprise a range of reds. They are used in plastics, textiles, and printing inks.

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

PR166-Cromophtal Scarlet

Pigment Type

organic, disazo

Chemical Formula

Properties

Pigment Red 166 has a yellowish red tone. It is semi-transparent and has high tinting strength.

Permanence

Pigment Red 166 has very good lightfastness.

Toxicity

History

Pigment Red 166 is a disazo condensation pigment, and is used in paints, plastics, printing inks, packaging, textiles, and many other applications.