LEARNING OBJECTIVES
■ Practise painting fat over lean
■ Add form to a small study of autumn leaves
■ Follow an oil-painting process
If you want to build up layers in an oil painting, you need to follow one of the golden rules, known as working ‘fat over lean’. This technique helps guarantee a painting’s longevity; not following the process can result in the surface of your painting cracking in the future.
Oil paint dries and hardens gradually on exposure to air (oxidisation). Initially, after a few hours or so, the paint will be a bit tacky but still workable. After a day or two, the oil paint might be ‘touch dry’, meaning that, although the surface of the paint feels dry, the paint beneath is still wet. After six months or more, oil paint can usually be considered dry, or ‘cured’, but this will depend on how thickly the paint has been applied.
Cracking can happen when thin, or ‘lean’, paint has been applied over thicker, or ‘fat’, paint. The thin layer will dry quickly, while the fat layer
