Encaustic (from the Ancient Greek enkaiein “to burn in”) is a beeswax based paint that is kept molten with pigments mixed in it. The word encaustic comes from Greek and means to burn in, which refers to the process of melting the paint.
This technique has many advantages. It has an excellent stability and brilliance of colours apart from not being attacked by moisture. It will not deteriorate, it will not yellow over time, and it will not darken. Encaustic paintings do not have to be varnished or protected by glass.
It cools immediately so that work has to be carried out quickly. The support has to be rigid because wax, once cooled becomes rigid and can break.
Encaustic has a long history. It was used by the Egyptians, Greeks and Romans, it reached its peak in Greece during the classical period (5th century b.C.).
Molten wax was applied stroke by stroke on a surface with a normal brush. Since la wax solidifies too quickly to allow mixing of colours, a heated metallic spatula called cautery was used to soften tones.

Perhaps the best known of all encaustic work are the Fayum funeral portraits painted in the 1st and 2nd centuries A.D. by Greek painters in Egypt. A significant Greek population had settled in Egypt following its conquest by Alexander. Many of these pieces have survived to our own time, and their colours have remained as fresh as any recently completed work.