A gesso layer is optional. Artists working in encaustic often paint directly on raw wood and other absorbent substrates without gesso.
Three reasons to use encaustic gesso:
- If you want to begin with a white surface, prepare the substrate with encaustic gesso.
- Encaustic gesso improves encaustic adhesion. So starting with a layer or two of encaustic gesso is a good practice.
- Encaustic gesso can be pigmented. You can create an underpainting establishing your design and values before adding wax.