Paint additives and coatings are substances that enhance the performance of paints, coatings adhesives, and other products. They can include thickeners, wetting agents, leveling agent, defoamers/spreaders or grasses that are anti-foaming (for latex paint), solvents/priming compound (to improve the penetration of adhesives and primers) UV inhibitors that stop the degradation of materials caused due to sunlight, antifoggants as well as retardants (when you are painting on wood). Once you like a fu