The process of decorating cold glass by removal of material can be done in several ways: direct engraving (wheel engraving and etching) or indirect engraving (acid etching and sandblasting). Direct engraving is practiced using either a diamond point, the oldest technique; an electric grinder, technique replacing the diamond point; or a grinding wheel. The diamond point resembles a metal stylus at the end of which is affixed a diamond fragment, and is used in much the same way as the engraver’s dry point is used for etching metal plates.

Although the qualities of the diamond were already well known to the Greeks, the process of diamond point engraving developed in the XVIth century and gave birth to a large quantity of masterpieces from Dutch and Bohemian glassworks. The stippled engraving which developed in Holland in the XVIIIth century is an exclusively Dutch innovation. The electric grinder looks just like a dentist’s burr -- that is to say a little wheel mounted on a flexible shaft that rotates at high speeds. It was first used at the end of the XIXth century in the United States. The engraving is done using crosshatching to create nuances of tone, or by stippling, offering even more delicate possibilities.

MATCHAM JOnathan, DREISER Peter, “ The Techniques of Glass Engraving”,Batsford LTD, Londres,1982 BRAY Charles, “Dictionary of Glass Materials and Techniques” A§C Black, Londres1995 OLIVIE Jean-Luc, PETROVA Sylva, “Verres de Bohême 1400-1989”, Flammarion, Musée des Arts décoratifs, Paris, 1990