They are made of white wax, soap, lac , mastic, sheep tallow, lamp black , and, for the hardest grade crayons, copal .
Lithographic crayons come in six different degrees of hardness.
The copal crayon traces a severe gray line on the stone while the softest grade, n.5, produces a fat black line. The softest grade crayon is difficult to work with because the warmth of the artist's hand can make it melt. These crayons can be held with a holder or then directly in the hand as one would hold a pencil. The crayon can also be held on its side in order to make longitudinal or transversal lines in one stroke obtaining large gray areas. The edge of the crayon can be used to obtain straight and fine lines.