Already in the 12th century, etchings depicted two glassmakers in similar postures, one standing and the other sitting at ground level. Although the industrial environment has been modernised, the technique remains the same. The first operator introduces, vertically, a mass of incandescent glass into a cast iron or steel mould heated with a blowtorch. The second operator operates a lever that presses the mould and prints a relief decoration on the glass bubble. This moulded-pressed glass technique – rediscovered and developed in the United States around 1825 – is still used in many factories, such as the Lalique crystal factory.