Conte crayon is an old medium that use to be called "red chalk" during the 1400's and was used
by the masters such as Michelangelo to practice and plan for their finished paintings. It's now
produced in France under the copyright name of “conte crayon". It's made of a clay-earth ingredient. I work with conte crayon on a gesso coveredboard. I apply several layers of gesso with a pallet knife which creates the cracked look, I then enhance the roughness with the conte crayon. Once the masterpiece in conte is finished, | varnish which deepens the tones and protects the surface. No glass is needed.