Present-Day Glass Decoration by Engraving, Etching, and Sand Blasting
JSGT 1936 V20 T218-T224
The decoration of glass can be carried out by appropriate shaping at the furnace, or by the introduction of colouring oxides in the glass when melted. The most perfect form of decoration, however, is by engraving; for this art, developed through thousands of years, yields glass objects of extraordinary beauty.
J. Drahonovsky