Great American Handmade Pastel - Spruce 1, 520.1
Product Details
- Description:
- Pastel
- Color:
- Spruce 1
- No.
- 520.1
Set colors may vary -
The vendor may substitute a color within a set due to stock issues without notice.
Colors on Monitors -
Due to differences in users’ monitors, the colors presented are an approximation of the true color.
Reviews
Pigment Information
This color contains the following pigments:
PW18-Calcium Carbonate
PB15:1-Phthalo Blue
PG17-Chromium Oxide Green
Pigment Name
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.
Pigment Name
PB15:1-Phthalo Blue
Pigment Type
organic
Chemical Name
alpha copper phthalocyanine
Chemical Formula
C32H16CuN8
Properties
Phthalo Blue PB15:1 is a structural variant of Phthalo Blue PB15 that produces more reddish tones.
Permanence
Phthalo Blues are completely lightfast and stable and are permanent for all paint uses. They are currently used in inks, coatings, and many plastics due to their stability and are considered a standard pigment in printing ink and the packaging industry.
Toxicity
Phthalo Blues have no significant hazards, although those made before 1982 contained some PCBs (polychlorinated biphenyls).
History
Developed by chemists using the trade name Monastral Blue, the organic blue dyestuff now known as Phthalo Blue was presented as a pigment in November 1935 in London. Its discovery was accidental. The dark color was observed in a kettle where a dye was being made from a British dyestuff plant. The demand for such a pigment came from commercial printers who wanted a cyan to replace Prussian Blue.
Pigment Name
PG17-Chromium Oxide Green
Pigment Type
inorganic
Chemical Name
chromium oxide
Chemical Formula
Cr2O3
Properties
Chromium Oxide Green is a dull, dense, willow or pale green color that is completely opaque. It has an average drying time and a low tinting strength. It is fairly flexible in oil form and is suitable for all purposes and mediums. This pigment is less versatile in mixtures than Viridian and Phthalocyanine Green, but mixes well with other colors without overpowering them.
Permanence
Chromium Oxide Green has excellent permanence, even at high temperatures.
Toxicity
Chromium Oxide Green is slightly toxic. Evidence of Chromium(III) carcinogenicity is inconclusive. Chromium(III) salts appear in greenish pigments such as PG17. Chromium(VI) salts, which appear in yellowish pigments, have been proven to cause cancer. 
History
Louis-Nicolas Vauquelin discovered the element chromium in lead chromate in 1797. It began to be used as an enamel and ceramic color in 1809, but it had limited use as a pigment until 1862, because of its cost. It is the most commonly used green for military camouflage because it appears the same shade as living foliage under infrared light.