Before the invention of glassblowing, glass was made by casting the molten mass into clay moulds. Also at later times glass has been pressed into moulds, and this kind of pressed glass has been popular after the industrialisation of glassmaking due to its low cost. Another old way of making glass was the mosaic technique, in which the vessel was made by joining minute pieces of glass. It is also possible to fashion cold glass by carefully cutting pieces off it, that is, by trimming or by cutting and engraving it.
