Encaustic painting (hot wax painting) is one of the oldest known painting techniques. The simplest hot wax painting is a combination of beeswax and pigment, melted and applied with a pallet knife or brush. There are often additions of Damar resin to harden the wax and make the paint more durable. The paintings are usually done on a wood panel but other substrates that are ridged and somewhat absorbent can be used. Ready made encaustic paints are available in blocks. The photo above shows a few of my favored colors from R&F.
The most common way to melt and mix the colors is on a heated pallet (often an electric griddle or skillet is used for this.) Recently I have been working in a more direct way, softening the block with a heat gun and drawing and rubbing the surface with it. I then fuse the paints together with the heat gun, often to the point that they become fluid and can be manipulated.
The term encaustic derives from the Greek word enkaustikos and means to burn in.