For thousands of years glassmakers have decorated glass by cutting designs into the surface. For many years glass was thin so the cutting was shallow by necessity, but in the 1600s advances in glassmaking made it possible to cut glass in new ways. Around the year 1675 Bohemian glassmakers devised a strong, high quality potash glass that could be deeply cut so that the design stood out in relief. Soon after a thick lead glass that could take deep cutting was developed in England. Glassware with cut designs became the rage and glassmakers responded by making more and more elaborately cut pieces.
During the 1820s a glassmaker devised a machine for creating pressed glass. The machine pressed molten glass into a mold, resulting in patterned glass that looked like hand cut glass pieces. The machine allowed glassmakers to mass produce “cut glass” designs and bring down prices so that the decorative glass was more accessible.
Both 19th century cut and pressed glass is popular with collectors, but cut glass tends to be more valuable. It can be difficult to tell cut glass from pressed glass, but there are a few clues to look for. Because cut glass was made by hand, the designs tend to have more irregularities than those made by machine. For example, on a cut glass decorated with diamond shapes there might be slight differences in the size and shape of different diamonds, whereas on the machine made pressed glass the shapes tend to look more alike. Also the thickness of the cut glass might be uneven. Take the weight of the piece into consideration, since cut glass tends to be significantly heavier than pressed glass. Pressed glass often has a line from the mold inside the glass. Also, the surface of the designs on cut glass tends to feel much sharper to the touch than that of pressed glass.
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