Glassware characterized by a series of facets, or patterns, cut into its surface. A marked pattern is roughed out on a glass object with a revolving abrasive wheel; the pattern is then smoothed by a sandstone wheel and polished in an acid bath. The Romans introduced a crude form of glass cutting in the 1st century AD. Modern glass cutting developed in Germany in the late 17th century with the production of a heavy, colourless crystal glass. After Bohemian glass became popular, English and Irish glassmakers adopted the technique. The prismatic styles of their products, notably Waterford glass, became popular in the U.S. after 1780.