Gum acacia


Hardened sap secreted by acacia trees, used in solution as a medium, vehicle, or binder for water-soluble pigments. Also used in adhesives, and, although it is slightly acidic, it is an ingredient in ice creams and candies. With much of it originating in the Sudan, gum arabic is so valuable that control of it has sometimes been violently contested. Also see base, resin, and watercolor.