Description

Carmine is a pigment – the aluminum salt of carminic acid Carmine, also called cochineal is a pigment of a bright-red color obtained from the aluminium complex derived from carminic acid. To prepare carmine, the powdered scale insect bodies are boiled in an ammonia or sodium carbonate solution. After separating the insoluble matter, the extract is treated with alum to precipitate the red solid. This precipitate is called carmine lake or crimson lake. Purity of color is ensured by the absence of iron. Stannous chloride, citric acid, borax, or gelatin may be added to modify the precipitation. The traditional crimson color is affected not only by carminic acid but also by choice of its chelating metal salt ion. For shades of purple, lime is added to the alum.[11][12] Naturally derived from insects but is also a lake dye.