Watercolor painting Watercolor paint consists of four principal ingredients: a pigment; gum arabic as a binder to hold the pigment in suspension; additives like glycerin, ox gall, honey, and preservatives to alter the viscosity, hiding, durability or color of the pigment and vehicle mixture; and evaporating water, as a solvent used to thin or dilute the paint for application. The more general term "watermedia" refers to any painting medium that uses water as a solvent and that can be applied with a brush, pen, or sprayer. This includes most inks, watercolors, temperas, caseins, gouaches, and modern acrylic paints. The term "watercolor" refers
Gum arabic since antiquity, sub-Saharan acacia gum has a long history as a prized export. The gum exported came from the band of acacia trees that once covered much of the Sahel region: the southern littoral of the Sahara Desert that runs from the Atlantic to the Red Sea. Today, the main populations of gum-producing "Acacia" species are harvested in Mauritania, Senegal, Mali, Burkina Faso, Niger, Nigeria, Chad, Cameroon, Sudan, Eritrea, Somalia, Ethiopia, Kenya, and Tanzania. "Acacia senegal" is tapped for gum by cutting holes in the bark, from which a product called "kordofan" or Senegal gum is exuded. "Seyal" gum, from