Gum. Gum arabic is a tree gum exuded by Senegalia senegal and Vachellia seyal. It is commonly used as a binder in watercolor paints, helping to suspend pigments and enhance their adherence to paper. Artists appreciate its ability to create smooth washes and vibrant colors. Also gum can be used in printmaking, particularly in lithography, where it acts as a resist to repel ink on certain areas of the plate. In other contexts, artists may use gums in mixed media, creating textures and effects by incorporating them into paint or applying them directly to surfaces. The flexibility and unique properties of gum allow for experimentation, making it a valuable resource for artists seeking innovative approaches to their work. The term gum arabic does not actually indicate a particular botanical source. The gum is harvested commercially from wild trees, mostly in Sudan and throughout the Sahel, from Senegal to Somalia. The name gum Arabic was used in the Middle East at least as early as the 9th century. Gum arabic first found its way to Europe via Arabic ports, and so retained its proper name. Gum arabic is a complex mixture of glycoproteins and polysaccharides, predominantly polymers of arabinose and galactose. It is soluble in water, edible, and used primarily in the food industry and soft-drink industry as a stabilizer, with E number E414. Gum arabic is a key ingredient in traditional lithography and is used in printing, paints, glues, cosmetics, and various industrial applications, including viscosity control in inks and in textile industries, though less expensive materials compete with it for many of these roles. Gum arabic was defined by the 31st Codex Committee for Food Additives, held at The Hague from 19 to 23 March 1999, as the dried exudate from the trunks and branches of Acacia senegal or Vachellia seyal in the family Fabaceae. A 2017 safety re-evaluation by the Panel on Food Additives and Nutrient Sources of the European Food Safety Authority said that although the above definition holds true for most internationally traded samples, the term gum arabic does not indicate a particular botanical source; in a few cases, socalled gum arabic may not even have been collected from Acacia species, instead coming from e.g. Combretum or Albizia.