Oil colors are made by mixing an adequate amount of cold-pressed linseed oil with a pigment to make a smooth buttery paint. When the paint is applied to a surface, the oil absorbs oxygen from the air and polymerizes to form a solid film, which binds the pigment to the canvas or panel. The dried film is tough and flexible, resistant to abrasion and water, and is not easily soluble in normal diluents, such as turpentine. The paint can keep well for long periods when stored in containers, such as tubes or jars, that exclude the air. It is desirable to use only as much oil as is absolutely necessary to bind the pigment in a film of good flexibility and adhesiveness. Since all linseed oil yellows to some degree the more oil that is used in the paint, the greater the amount of subsequent yellowing.