Glass engraving is a process of ‘drawing’ on a glass surface. It is a shallow intaglio process in which the forms are worn away beneath the surface of the glass by slow abrasion. The process is delicate, requiring great patience and a high degree of skill. The tools used consist of a small lathe with copper wheel disks mounted on mild steel spindles, Wheels are fed with an abrasive paste of vegetable oil with fine emery powder,
slowly grinding away the glass.
Alasdair now concentrates on the ancient art of Cameo Glass, which starts with a specially blown vessel ‘blank’ (with several layers of glass, each of a different colour) Using an engraving wheel, portions of the outer layers are slowly and selectively carved back to reveal a multi-coloured design standing proud of the surface. The effect is something like a finely carved
ivory tableau against a subtle translucent coloured glass background. “My own brass engraving lathe, which I use with pleasure an a daily basis, was manufactured in Blottendorf, Bohemia around 1870. It seems probable it arrived in Sydney about 1880 along with one of several prominent glass engravers from England. It came into my possession in1995.”
Rish uses a sandblasting technique, where pressurized air is used to force abrasive sand through small nozzles to etch the glass surface. She masks the surface of cold glass that has been hand blown in colours to her specifications, then draws into it her image. The masking is then selectively removed using this outline as a guide. Over many stages, using varying air pressure, she painstakingly creates the most beautifully detailed designs of nature and wildlife.