The Encaustic process involves brushing melted wax onto a drawing or painting, for example, and then using a heat gun or hot iron gizmo to blend and even out the surface. There are all sorts of things you can do beyond that, like gouging areas or lines, filling them with color, embedding things in the wax, and more. This process has been around for hundreds of years and has experienced a resurgence among contemporary artists, who have the benefit of modern tools that make it all easier.
Here is Judy's table top set-up: An electric griddle set at 200 degrees keeps cans of wax in a liquid state. Each can is a different color or type of wax. She works at the left, over sheets of wax paper that catch drips of wax that can be recycled. On the wall in the background, you can see the series of drawings Judy has been enriching with encaustic.
Here you can see the melted wax on the griddle, ready for use. A paint brush in each can sits at the ready.
Here is my result. The encaustic deepened the richness of the colors of the drawing and gave a lovely patina to the surface.