Paint has four major components: pigments, binders, solvents, and other additives. Pigments serve to give paint its color, texture, toughness, as well as determining if a paint is opaque or not. Common white pigments include titanium dioxide TiO2 and zinc oxide ZnO. Binders are the film that forms as a paint dries and they affect the durability, gloss, and flexibility of the coating. Polyurethanes, polyesters, and acrylics are all examples of common binders. The solvent helps adjust the curing rate and viscosity of the paint in its liquid state. The solvent evaporates off as the paint dries. There are two types of solvents: solvent-borne and water-borne. The additives that are incorporated into paints are a wide range of things which help to effect the properties of the paint and the final coating. The main additives added to many paints are surfactants.