I work the base in different ways. Sometimes I start with a digital painting on my tablet. I use procreate as program to make a digital sketch for using as underpainting. Or I start of with watercolor or ink as an underpainting on paper. The paper is glued to a firm steady surface. Then I start with layers of beeswax (non colored and colored with powder pigment) In between I sometimes paint some more with oil pastel or alcohol ink.