Carmine
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Carmine, also called cochineal, cochineal extract, crimson lake or carmine lake, is bright-red color pigment obtained from the aluminium complex derived from carminic acid.
Contents
Properties
Carmine is a fugitive color, whose fading is influenced by different factors such as light, humidity, or even the glass color of the frame.
Carmine is a reddish powdered solid, insoluble in water.
Availability
Can be bought online or from suppliers.
Preparation
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. 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.[1]
Projects
- Red pigment
Handling and safety
It is not a toxic compound, but it may cause allergy is some people.
Should be kept in closed containers, away from light and humidity.
No special disposal is required.
