I’ve done a few paintings where I painted directly on sheets of aluminum. When doing this I like to leave portions of the metal exposed in the final painting as the shimmering surface adds some interesting effect.
To do a painting like the one shown I start by masking out the portions where the metal will be exposed, in this case rocks within a mountain stream. After the masking tape has been applied to the selected areas, I cover the entire surface with a metal primer. The primers will dry in a few hours and I begin painting the surface. I like to use acryl gouache to do paintings on metal – this is a multi-surface paint with good adhesion since it dries matte and is opaque there is little chance for streaking or surface exposure. When the paint is finished I’ll remove the masking tape and add some highlights to the exposed metal.
Shown - Mountain Stream #1 12x18" Acryl Gouache on Aluminum