Encaustic

Encaustic is a painting technique in which pigments are mixed with molten wax, usually beeswax. This method allows for rich colors and extraordinary durability: ancient portraits painted with encaustic retain their freshness for centuries. For encaustic work, a hot iron spatula or brush is used, and the surface is usually heated for better adhesion.

The method is believed to have originated in Ancient Greece and was especially popular in Roman Egypt—the famous Fayum mummy portraits were made this way. Encaustic requires special skill: if you overheat the wax, the image will "melt away." In contemporary art, it is sometimes revisited for the effect of depth and texture—color literally begins to glow from within.