Color Swatch created using Heavy application/diluted application and was applied on Cold Press Watercolor Paper (150 lb) material.
This color contains the following pigments:
PY40—Cobalt Yellow
Pigment Type
inorganic
Chemical Name
potassium cobaltinitrite
Chemical Formula
K3[Co(NO2)6] • H2O or CoK3N6O12
Properties
Cobalt Yellow is an expensive, transparent, very pure yellow with only fair hiding power. It is reliable in watercolor and makes particularly good tints. However, it must be carefully manufactured in oil form, or it can brown. Cobalt Yellow is known for good mixing quality with all other pigments, and it is useful in glazes and for tinting.
Permanence
Cobalt Yellow has good permanence and lightfastness, and it can withstand strong sunlight.
Toxicity
Cobalt Yellow is highly toxic by inhalation or ingestion. The ingestion of this pigment has caused cyanosis (low oxygen levels in the blood) due to methemoglobinemia.
History
Cobalt comes from the Middle High German word kobolt, an underground goblin, because miners thought cobalt harmed silver ores. The discovery of the potassium and cobalt compound used to make Cobalt Yellow is credited to N.W. Fischer in Breslau in 1848. It was not introduced as an artists’ pigment until 4 years later, by Saint-Evre in Paris. During the previous century, it was considered the only color that could reasonably replace Indian Yellow.
Alternate Names
Aureolin.
PY3—Hansa Yellow
Pigment Type
organic
Chemical Name
n/a
Chemical Formula
C16H12CL2N4O2
Properties
This Hansa yellow is a transparent yellow. It has great brightness and tinting strength and its drying time ranges from average to slow.
Hansa Yellow makes more intense tints and cleaner secondaries than Cadmium Yellows, especially when mixed with other organic or modern colors like Phthalo Blue and Green. Because they are more transparent, they have great value as glazing colors.
Permanence
This Hansa Yellow has fair to good permanence, particularly in the lighter 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.
Alternate Names
Arylide, Arylide Yellow, Azo, Brilliant Yellow, Monoazo, Monolite Yellow, Permanent Yellow.
