The painting and the relative pictorial procedure characterized by the use of colours mixed with wax, treated after the application of a heat source (hot charcoal that one identifies with the ancient cauterium) and then polished with rags. Encaustic paintings were realized throughout time with varied procedures and techniques, and only today identified, even though the studies and experiments conducted in a particular way in the second half of the 18th Century parallel the growth of interest in encaustic painting discovered in Ercolano and Pompeii. Widely practiced from the times of ancient Egypt (15th Century BC) until the Byzantine Age, the technique of encaustic painting resembles in the use of waxing the surface of the mural painting in the Middle Ages and in the Renaissance. In this case, the procedure is simply the spreading of wax (or with a mixture of cooked linseed oil and wax) over the surface of the painting, conferring a particular tonality and brilliance of the colours. Also see Stucco Lustro.