A mug is a sturdily built type of cup often used for drinking hot beverages, such as coffee, tea, hot chocolate or soup. Mugs have handles and hold a larger amount of fluid than other types of cup. Usually a mug holds approximately of liquid; double a tea cup. A mug is a less formal style of drink container and is not usually used in formal place settings, where a teacup or coffee cup is preferred. Shaving mugs can be used to assist in wet shaving. Ancient mugs were usually carved in wood or bone or shaped of clay, while most modern ones are made of ceramic materials such as earthenware, bone china, porcelain or stoneware. Some are made from strengthened glass, such as Pyrex. Other materials, including plastic, steel and enameled metal are preferred where break resistance and reduced weight are at a premium, such as for campers. Techniques such as silk screen printing or decals are used to apply decorations; these are fired onto the mug to ensure permanence.