OIL PAINTS ARE MADE BY MIXING and grinding pigment with a drying vegetable oil such as
linseed oil. The paint can be applied to many different surfaces and textures—the most common being canvas. Before painting, the canvas is stretched on a wooden frame and its surface is prepared with layers of size (glue) and primer. The two main types of brushes used in oil painting are stiff hog hair bristle brushes— generally used for covering large areas; and soft hair brushes made from sable or synthetic material—generally used for fine detail. Other tools, including painting knives, can also be used to achieve different effects. Oil paint can be applied thickly (a technique known as impasto), or can be thinned down using a solvent—such as turpentine. Varnishes are sometimes applied to finished paintings to protect their surface and to give them a matte or gloss finish.
