Although manual forming methods date back thousands of years, they are still used
today by skilled artisans, either in production or for artworks. Hand modeling involves
the creation of the ceramic product by manipulating the mass of plastic clay into the desired
geometry. In addition to art pieces, patterns for plaster molds in slip casting are
often made this way. Hand molding is a similar method, only a mold or form is used to
define portions of the geometry. Hand throwing on a potter's wheel is another refinement
of the handicraft methods. The potter's wheel is a round table that rotates on a vertical
spindle, powered either by motor or foot-operated treadle. Ceramic products of
circular cross-section can be formed on the rotating table by throwing and shaping the
clay, sometimes using a mold to provide the internal shape.