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:
PW18—Calcium Carbonate
Pigment Type
inorganic
Chemical Name
calcium carbonate
Chemical Formula
CaCO3
Properties
Calcium carbonate, the mineral constituent of chalk, is a low tinting strength, inexpensive white pigment that is often used is a buffer and filler. Because of its low tinting strength, it is overwhelmed by other colors. It is used in gesso and other coatings to give the surface more tooth, a desirable characteristic for some painting techniques.
Permanence
Calcium carbonate is lightfast. Like all carbonates, it reacts with strong acids
Toxicity
Calcium carbonate is completely non-toxic, and is used in many food, cosmetic, and pharmaceutical products. However, excessive consumption is not recommended.
History
Naturally occuring chalk deposits have been mined since prehistoric times. Rocks and minerals that contain calcium carbonate include aragonite, calcite, vaterite, chalk, limestone. marble, and travertine. Calcium carbonate is the principle component of lime, used in many agricultural and industrial applications.
Alternate Names
Chalk
PBk28—Black Spinel
Pigment Type
inorganic
Chemical Name
copper chromite black
Chemical Formula
n/a
Properties
Black Spinel is a very neutral opaque black pigment, excellent for tinting to create neutral grays.
Permanence
Black Spinel has excellent lightfastness.
Toxicity
Black Spinel is mildly toxic. The pigment itself has an extremely fine particle size. It causes irritation and ulceration to skin. Respiratory exposure and exposure to dust are serious concerns.
History
Black Spinel is much more expensive than carbon-based blacks. Its use as a pigment has been limited to applications where a truly neutral black or gray tone is needed.
Alternate Names
Jet Black, Ebony Black, Neutral Black, Copper Chromite Black.
PBr33—Zinc Iron Chromite Brown
Pigment Type
inorganic
Chemical Name
zinc-iron-chromite spinel
Chemical Formula
ZnO + Fe203 + Cr2O3
Properties
Zinc Iron Chromite Brown is a dark reddish brown pigment that is opaque and staining.
Permanence
Zinc Iron Chromite Brown is exceptionally lightfast, heat resistant, weather resistant, and durable.
Toxicity
Zinc Iron Chromite Brown has not been identified as hazardous, but it is likely to contain impurities that are irritating to the skin or lungs. Pigment from natural ores may contain traces of heavy metals.
History
Because of its exceptional durability and heat resistance, Zinc Iron Chromite is used as a brown pigment in ceramics.
Alternate Names
Shepherd Brown 12
