A heavy, thick, round or rectangular plate of light brown stone used to duplicate the baking qualities of the brick floors of some commercial bread and pizza ovens. A baking stone should be placed on the lowest oven shelf and preheated with the oven. The item to be baked is then placed directly on the baking stone in the oven. Dough-filled pans or baking sheets may be placed on the stone for a crisper, browner crust. When not in use, the stone can be left in the oven. Baking tiles, which are usually less expensive than baking stones, are thick, unglazed quarry tiles 8 to 12 inches square. Look for high-fired tiles, which do not crack as readily as low-fired tiles. Also available are sets of eight small, 8- by 4-inch clay tiles that come on an aluminum tray for ease in handling.