Cochineal 4 oz vol
|Common Names (Pigment):||
German: Cochenille, Koschenille, Nopalschildlaus
Spanish: cochinilla, grana cochinilla, zacatillo
Origin and History
The Carmine Cochineal or cochineal grana, as it is known in Central and South America, is an insect that lodges on some cactus of the Opuntia genus (Fiscus Indica and others). Cochineal feeds itself on cacti sap for survival and so is harvested in cacti plantations. The Aztecs called it nocheztli, which means Sangre de Tuna (tuna's blood), and was used in homage to their kings. Various studies have shown that countless tunics and gowns used by the royalty of Aztec, Pre-Colombian, Inca, Pre-Inca, Paracas and Nazca necropolis cultures were dyed with cochineal.
We purchase cochineal from growers in the Elqui Valley of Chile where one of the highest quality cochineal is harvested under strict governmental regulations. Our cochineal contains an average of 22% carminic acid measured using FCCII method. Our product is cultivated and obtained from prickly-pear plantation. Our product consists of 99% dried cochineal and 1% prickly pear residues.
Preparation of Lake Pigment
Pigments and dyes are not identical, although there are cases in which the same coloring matter which yields a dye or stain may give rise to a pigment. A pigment is, in fact, a substance which is insoluble in the vehicle with which it is mixed to make a paint, while a dye is soluble. A lake pigment is a natural organic pigment prepared when a dye has been precipitated on a powdered, colorless, inorganic substrate. The term derives from the Latin word lacca, used in the Middle Ages to denote both lake pigments and the Lac dye. Because of its transparency, aluminum hydroxide is the most commonly used substrate or carrier. Barites, such as barium sulfate, provide an opaque lake pigment. Other compounds used as carriers are: chalk, clay, gypsum, tin oxide, zinc oxide, white earth, and green earth. Often a mordant, such as tannic acid, lactic acid, or sodium phosphate, is used to fix the dye to the substrate. Carmine lake for artists' pigments are prepared from cochineal extract by adding alum and precipitating with an alkali.
Permanence and Compatibility
Carmine lakes have little resistance to light and weather; they fade readily even under incandescent illumination. Oil paints and watercolors based on modern carmine lakes exhibit a lightfastness equivalent to between 1 and 2 on the British Standard 1006:1971 blue-wool scale. Carmine lakes precipitated on tin mordants exhibit higher lightfastness. Carmine lakes are not affected by hydrogen sulfide, but are affected by basic and acidic conditions. Thus, although suitable for watercolor, size, oil and egg tempera, their resistance to the alkalinity of lime and waterglass would make them unfit for such use.
Oil Absorption and Grinding
No data has been published on the oil absorption and grinding qualities of carmine lake pigments.
Cochineal is not toxic, and in fact is used by industry to color food and beverages. Care, however, should always be exercised when handling dry powders (such as when the cochineal is pulverized) so as not to inhale the dust.
|Colour Index:||Natural Red 4 (75470)|
|Chemical Name:||Carminic Acid (7-a-D-glucopyranosyl-9,10-dihydro-3,5,6,8-tetrahydroxy-1-methyl-9,10-dioxo-2-anthracenecarboxylic acid)|
|ASTM Lightfastness Rating|
|Processing Time||Usually ships the next business day.|
|Size||4 oz vol jar|