It could be made of glass. Some are made of paper. Others are made of ceramic or plastic. They can be square, round or oval. No matter its composition, a bathroom tumbler is a fixture on any bathroom vanity. Whether it is used to rinse your mouth after brushing, to hold your makeup brushes or to soak your dentures before going to sleep, a bathroom tumbler, or bathroom cup, is a necessary accessory in all active bathrooms, so much so that hotels keep the small, handle-free cups in their bathrooms knowing that guests rely on them for several uses.