During the 1890s, Tiffany experimented with a variety of decorative arts, including blown glass, metalwork, pottery, and enamels. Enamelware is composed of glass and glass silicate, with metallic oxides added to provide color. This surface is applied to copper (and other metals) and fired at a high temperature. Copper was used as the base because it was thin and created a surface for unpredictable reactions in color. Closely linked to glassmaking, enamels provided great versatility and flexibility in color range, an important feature in Tiffany's artwork, as well as a shimmering surface when light struck. The enamel department, led by women such as Patricia Gay and Julia Munson, produced small decorative objects, including bowls, vases, and covered boxes that were made in limited production for about nine years from 1898 to 1907.