Carbon dust

Dust is prepared by rubbing carbon pencils against an abrasive surface, such as a metal file.

The technique was popularized by Max Brödel (1870-1941)[1][2] and became widely used among medical and scientific illustrators in the twentieth century.

[3] Brödel described his technique in detail while drafting a proposed book on medical illustration, that was later published as an appendix in his biography.

In 1894 after arriving in Baltimore and after some experimentation he began using the dust of Wolff carbon pencils applied to Ross .00 stipple board.

He carved rubber erasers, bits of cork and chamois, then secured them in brass charcoal holders for use on drawings.