Sandblasting

Sandblasting is a surface finishing method built on the principle that abrasive particles blasted by compressed air wear away the softer parts of the wood while the harder tissue stays in place. In pipe making, the goal isn't just a matte look: done right, the annual rings and fibers of briar stand out in relief, turning the grain — otherwise only visible as a color difference on a smooth surface — into a tactile texture.

History

The technique's industrial roots predate the pipe. In his 1870 American patent (108,408), inventor Benjamin Chew Tilghman described uses for pressurized abrasive ranging from etching glass to sharpening files to exposing grain in wood. Its move to pipes came half a century later: Alfred Dunhill's British patent process for the finish — begun in 1917 and combining oil soaking with heat treatment — turned the shell-like surface into a commercial category. See The History of Dunhill's Shell Briar for details.