Cracking Off
From Melting Pot Wiki
The removal of an object from off a pontil. After cooling and scoring, as opposed to shearing, of the hot glass, the blow pipe is softly knocked and the object drops into a sand tray, V-shaped holder held by an assistant. Also the technique for making a rim on blown vessels, using a piamond point or other sharp stone and a trail of glass, and the vessel is separated from the overblow.
