The glasses of the Zalto Glass House are not only about design. They are produced without the addition of lead oxide and are resistant against clouding. Despite its feather-light weight and delicate edges, the Denk`Art series of glasses maintains all the best attributes of a modern glass as far as care and longevity are concerned. Denk`Art glasses may be washed in a dishwasher and should be considered your everyday glass as well as the glass to use for your most special occasions.