An ancient method of painting, recorded by Pliny, of fixing pigments with heated wax. It was probably first practiced in Egypt about 3000 BC and is thought to have reached its peak in Classical Greece, although no examples from that period survive. Pigments, mixed with melted beeswax, were brushed onto stone or plaster, smoothed with a metal spatula, and then blended and driven into the wall with a heated iron. The surface was later polished with a cloth. It was particularly used for the Fayum mummy-portraits of Roman Egypt. Leonardo da Vinci and others attempted unsuccessfully to revive the technique. North American Indians used an encaustic method whereby pigments mixed with hot animal fat were pressed into a design engraved on smoothed buffalo hide.