Color Swatch created using heavy application/medium application/50% tint and was applied on acrylic primed canvas (7 oz) material.
This color contains the following pigments:
PY83—Diarylide Yellow 83
Pigment Type
organic, disazo
Chemical Name
n/a
Chemical Formula
C36H32Cl4N6O8
Properties
Diarylide Yellow is a semi-opaque, moderately staining, intense deep reddish yellow pigment with good tinting strength.
Permanence
Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists’ color. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.
Toxicity
Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.
History
Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.
Alternate Names
Benzidine Yellow, Diazo Yellow.
PY17—Permanent Yellow
Pigment Type
organic, disazo
Chemical Name
Benzidine Yellow GG
Chemical Formula
n/a
Properties
Pigment Yellow 17 is a somewhat greenish yellow that has very high tinting strength and good resistance to solvents.
Permanence
Pigment Yellow 17 has good lightfastness if prepared using the proper procedures. Because procedures for preparing PY17 vary, artists may want to conduct their own lightfastness tests to verify that the manufacturer has selected quality pigment.
Toxicity
Benzidine dyes are not bioavailable. Although benzidine-based dyes can be reduced to their amine precursors in vivo, creating a compound that is carcinogenic, benzidine dyes are believed to be so insoluble in water that they are unlikely to be absorbed in a quantity sufficient to be carcinogenic.
History
This Benzidine Yellow dye was first reported by Esitelty in 1949. Initiailly, it was reported to be less lightfast than yellow monoazo pigments, which limited its usefulness. A method for making Pigment Yellow 17 more permanent was patented in 1972 (United States Patent 3785843), and the improved dye became known as Permanent Yellow. Permanent Yellow 17 is widely used in printing inks, textile dyes, paints, plastics, and coatings.
Alternate Names
Benzidine Yellow GG, Diarylide Yellow 17
PBr7—Raw Umber
Pigment Type
earth
Chemical Name
hydrated iron oxide
Chemical Formula
α-FeO3+(OH) or Fe2O3 × MnO2
Properties
Raw Umber is a cool, transparent brown ranging from yellowish brown to greenish brown. It has surprisingly good tinting strength, a high level of opacity, mixes well with greens, and is quick drying in oil form. It has excellent color properties and can create a variety of subtle, clear tints when mixed with white. It grays when mixed with blue and white. Raw Umber can tend towards chalkiness in dark mixes in oil form.
Permanence
Raw Umber has excellent permanence.
Toxicity
Raw Umber itself is considered non-toxic. If contaminated by manganese compounds, it may be highly toxic if inhaled and moderately toxic if ingested.
History
This pigment gets its name from the Latin word umbra, meaning shadow or shade. Its full name is listed as terra di ombra, meaning earth of shadow/shade, due to its original extraction from the area of Umbria, Italy. It has been used as a pigment since prehistoric times. Currently, the finest umber comes from Cyprus.
Alternate Names
Chestnut Brown, Euchrome, Jacaranta Brown, Mars Brown, Raw Brown, Sicilian Brown. Cyprus Umber, Turkey Brown, and Turkey Umber are the best quality umbers.
