Lathe-working in Roman Glassware

Lathe-cutting was easily the most persistent means of decoration from Hellenistic times through the early Byzantine era. Most likely, Roman glassworkers were imitating patterns of mold ridges that were cast in low relief on pottery and silver vessels of the day. A thin-walled beaker could be mounted on a lathe and its surface lightly scored with the edge of a wheel or a scribing point, to create patterns of lines spaced in any rhythm. A thick-walled vessel could be decorated with similar groups of lines or with grooves of varying depth and width.

In part, the stimulus for lathe-cutting of glass was a mimicry of vessels carved from rock crystal; vessels so highly prized that they also rated being mimicked in silver and bronze. The noveau riche Romans were willing to spend a fortune on such items, by way of copying the prevalent tastes of the imperial circle. 

The surface of a rock crystal vessel could be sculpted in low relief, so its imitation in glass called for a robust body that could withstand the pressures of extensive lathe-working. Through the production of weighty and colorless, relief-decorated tablewares, it is no mere chance that the earlier tradition of glass-casting did continue for a full five decades after its eclipse elsewhere in the industry. Rock crystal also lent itself well to faceting, so the free-blowing side of the industry developed the skill of producing thick-walled blanks, parts of which could be cut away and smoothed on a lathe, before the outside was cut and ground with patterns of interlocking or overlapping diamonds and ovals.