Until the nineteenth century, the best pencil graphite came from Borrowdale, in England. As a result of the French Revolution, the supply of English graphite was permanently embargoed, creating a problem for the French pencil-maker, artist and scientist Nicholas-Jacques Conté.
Conté had opened his pencil factory, later known as Blanzy-Conté Gilbert, with his brother Louis in 1793. For the business to survive, he had to find another way to produce a workable writing medium.
In 1795 Conté developed a method that involved mixing powdered local graphite with clay, waxes and water, firing the mixture in a kiln and forcing it into wooden casings.
This process allowed the French to produce their own pencils. It also permitted manufacturers to control the hardness of the lead, which in turn controlled the darkness of the mark made by the pencil.
The process was so successful that Conté became synonymous with pencil, and Conté crayons are valued and used by artists today.