A water soluble gum commonly used in binding media of paints. Gum arabic is the amorphous exudate from the stem of several species of Acacia trees, especially Acacia senegal, found in tropical and subtropical areas of the world. Most gum arabic coming from the sub-Sahara region in Africa. Gum arabic contains arabinose, galactose, rhamnose, and glucuronic acid. It is sold in the form of round lumps, granules, thin flakes or as a powder; all of which may be white or slightly yellowish. Gum arabic is completely soluble in hot and cold water, yielding a viscous solution. However, heating a gum arabic solution to the boiling point will cause it to darken and will change its adhesion properties. Solutions of gum arabic will precipitate or gel with the addition of ferric salts, borax, alcohol, or sodium silicate. Gum arabic is used in watercolour paints. It is listed as an organic additive for stucco marble preparation according to literature. Synonyms: gum arabicum; kordofan; picked turkey; white sennar; senegal gum; ghezineh gum; gomme blonde; gomme blanche; gum acacia, East India gum; kami; wattle gum. Wittenburg (1999); Museum of Fine Arts, Boston (2000). [J. Cassar, R. de Angelis]