I work on a clay panel (aquabord produced by Ampersand Art, Which is an acid-free textured clay surface that absorbs watercolors like a fine paper). My painting process consists of many layers of translucent watercolor pigment on the wet white clay surface.
I work with a limited pallet, keeping it to no more than 5 colors. Working from light to dark colors, I lift the pigment out when necessary, to bring the light or whites back. All the whites in my painting are absent of watercolor pigment. I never mask a paint.
I seal the finished watercolors with several light coats of a spray UV coating and then a layer of liquid varnish. The painting does not need to be framed behind glass.