The term cameo refers to a design produced in relief in one or more colors on a background of a different color. Cameo glass is a type of glass in which glass of one color is covered, or cased, with one or more layers of glass in contrasting colors. The outer layers are then carved, cut, acid etched, or engraved to produce a design that stands out from the background. The first cameo glasses were made by the ancient Romans. The genre was revived in Europe and, to a lesser extent, in America during the nineteenth century.