thoroughly melt the paraffins, candelilla wax, ozocerite, and powdered rosin in a double boiler. Then slowly add the graphite and copper dust, constantly stirring, until all is incorporated and a homogeneous, thick paste is obtained. Spread the paste on a large glass slab, cover it with another slab, and compress it until the mass is 0.25-inch thick. Chill slightly and cut into 0.25 inch wide strips with a hot knife. If preferred, "Aquadag" (a colloidal suspension of graphite in water) may be used to coat the surface.
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