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 insoluble in water upon exposure to ultraviolet light. In the final print, the acacia gum permanently binds the pigments onto the paper. Gum arabic is also used to protect and etch an image in lithographic processes, both from traditional stones and aluminum plates. In lithography, gum by itself may be used to etch very light tones, such as those made with a number five crayon. Phosphoric, nitric or tannic acid is added in varying concentrations to the acacia gum to etch the darker tones up to dark blacks. The etching process creates a gum adsorb layer within the matrix that