Materials
The encaustic technique allows you to do two things that you can't with oil. With wax you can immediately paint one layer on another without obliterating what went before, and you can manipulate the paint at any time after it has been applied.
You can also add linseed oil and turpentine if you want, there is a contiuum going from pure oil painting to pure wax painting. Van Gogh used a lot of wax in his oil painting formula so that the brush strokes would stay prominent after they dried.
History
Encaustic wax is among the most ancient painting techniques. It was
practiced in ancient Egypt, Greece and Rome. The most famous examples of encaustic wax painting from ancient times are the funeral portraits from Fayum in Egypt, which date from the second century AD. Some Australian Aborigines have used patterns made with knobs of beeswax to augment their cave paintings. In one case the wax has remained perfectly fresh and unchanged for fifteen thousand years.
Maintenance
Unlike an oil painting, which requires cleaning with spirits and revarnishing occasionally, an encaustic wax will require nothing more than an occasional light wipe with a soft, dry, lint free cloth to remove dust. If the painting has become very grubby, soapy water might be employed, but detergents or other proprietary cleaning products must be used with extreme caution if at all.
Beeswax, formula C30H61OCOC15H31, is a very stable and chemically inert material. Pigments suspended in beeswax do not undergo chemical changes to the same extent that they do in oil paintings, and the wax does not darken over time like the linoxin in the linseed oil of an oil painting, so the colours retain their brilliance and saturation for a longer time. Because of the inherent preservative properties of beeswax, encaustic paintings have the potential to last for thousands of years.
Peter Wilkin, 29th April 1997
In Europe of the Middle Ages encaustic wax became unpopular because of the invention of oil painting and its relative ease. With the twentieth century came the widespread use of electricity, and it is now quite simple with the use of a heating element controlled by a thermostat to melt the wax and keep it at an ideal temperature to work with. Many painters have discovered the advantages of encaustic wax painting now that they can use various electrical appliances for their equipment, and the technique has for some years now been making a resurgence.
Although dammar resin has been added to the wax to harden it and raise its melting point, encaustic wax paintings are flammable and care should be taken to hang them away from strong heat and naked flame. (As you would with any other kind of painting or wall hanging anyway)
