Conte Sketching Crayons

Conté crayons, are a drawing medium composed of compressed powdered graphite mixed with a wax or clay base, square in cross-section. They were invented in 1795 by Nicolas-Jacques Conté, who created the combination of clay and graphite in response to the shortage of graphite caused by the Napoleonic Wars. Conté crayons had the advantage of being cost-effective to produce, and easy to manufacture in controlled grades of hardness.  

They are frequently used on rough paper that holds pigment grains well. They can also be used on prepared primed canvases for underdrawing for a painting. The sticks' square profile make Conté crayons more suitable for detailed hatched work as opposed to the bolder painterly drawing style demanded by soft pastels.