Color Swatch created using heavy to light application and was applied on 100 lb (163 gsm) drawing paper material.
This color contains the following pigments:
PY184—Bismuth Yellow
Pigment Type
inorganic
Chemical Name
bismuth orthovanadate or bismuth vanadium oxide
Chemical Formula
BiVO4
Properties
Bismuth Yellow is an intense, light value, semi-opaque yellow pigment with good tinting strength.
Permanence
Bismuth Yellow has excellent lightfastness.
Toxicity
Bismuth orthovanadate is harmful if swallowed. It is irritating to the eyes, respiratory system, and skin. Exposure may cause conjunctivitis, rhinitis, and reversible irritation of the respiratory tract. More severe cases may cause bronchitis, bronchospasms, and asthma like disease. It may cause polycythemia, red blood cell destruction and anemia, albuminuria and hematuria, gastrointestinal disorders, nervous complaints, and severe cough. However, bismuth vanadium oxide is completely insoluble in water. This limits absorption and biological activity. In waterbased paints, it must be suspended in a binder vehicle. Because of low absorption, such clinical symptons are primarily limited to cases of long-term occupational exposure.
History
Bismuth orthovanadate occurs naturally in several minerals. Although it was synthesized in the 1920s, it was not developed as a commercial pigment until the 1970s.
Alternate Names
Permanent Lemon Yellow, Vanadium Yellow.
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.
PB27—Hooker’s Green
Pigment Type
mix of organic pigments
Chemical Name
n/a
Chemical Formula
C30H18FeN3O6Na
Properties
Hooker’s Green is a bright olive-green often sold in a yellowish shade and a bluish shade. Its transparency can range from dull and dark to bright and light because lightness and chroma vary based on manufacturer. Modern varieties have a rich, dark tone that provides a great range when mixing. Hooker’s Green is particularly good for landscape painting when a larger range of foliage is required. Dioxazine Violet is the best mixing compliment in watercolor form.
Permanence
The permanence and lightfastness of Hooker’s Green varies by brand. As a composite pigment historically mixed from Prussian Blue and Gamboge, its permanence is only fair. Modern replacements for Hooker's Green tend to be mixed with components that have more permanence, such as Phthalocyanine Green, Burnt Umber, and sometimes Hansa or Cobalt Yellow.
Toxicity
Hooker’s Green can be hazardous, but the toxicity level depends on the specific pigments used by each individual manufacturer or brand.
History
This pigment was originally an unreliable mix of Prussian or Iron Blue and Gamboge. Later, it became a more reliable mix of Cadmium Yellow and Phthalo Blue or Green. It was a staple green for 19th century landscape and botanical painters. Most modern Hooker’s Green paints are yellow greens with a hue angle around 140, or a mix of Phthalo Green and Burnt Umber.
Alternate Names
n/a
