The Greek word encaustic means "to burn in." While beeswax is the primary binder, artists often add a little tree resin to harden the paint and raise its melting point.

Known as Fayum mummy portraits, these highly realistic wax paintings were bound over the faces of mummies to memorialize the deceased.

Because hot wax cools and solidifies almost instantly, Johns could freeze his heavy texture in place and even embed real newspaper scraps into the canvas.

Applying a heat gun or blowtorch permanently bonds the individual wax layers together and to the substrate, preventing the painting from flaking apart over time.