Porcelain is made with kaolin clay which retains it bright white color when fired. It is usually covered with a clear glaze, which allows the white body to show. Porcelain becomes vitrified during the second firing of a two fire process. The second firing is typically at a hotter temperature than the first, and can make decorating the surface more difficult than stoneware. This second firing also causes the finish to be harder and more brittle. The composition of porcelain clays is usually more malleable than the clays used for stoneware which allows for more intricate and detailed shapes.