Glass engraving is done with copper wheels, which rotate at a high speeds. There are about 150 sizes of glass engraving wheels on the market. A small stream of oil and abrasive flows against the front edge of the rotating wheel.
The glass engraver then lifts his or her work up to the wheel and moves the piece to create the desired design.. Whke the abrasive rubs between the glass work and the copper wheel some of the abrasive then becomes imbedded. Where is the glass imbedded you ask? It is imbedded in the copper wheel. This makes the wheel have a better cutting action.