Traditional oil painting techniques often begin with the artist sketching the figure onto the canvas with charcoal or a "wash," which is thinned paint. Oil paint can be mixed with turpentine or artist grade mineral spirits or other solvents to create a thinner, faster drying paint. Then the artist builds the figure in layers. A basic rule of oil paint application is 'fat over lean.' This means that each additional layer of paint should be a bit oilier than the layer below, to allow proper drying. As a painting gets additional layers, the paint must get oilier (leaner to fatter) or the final painting will crack and peel. There are many other painting media that can