Libbey Glass Duratuff LinQ Short Drinking Glasses, Set of 4. New. Glasses are made of durable Duratuff Glass with a panelled design. Gray in color. Dishwasher safe. Stackable glasses for easy storage. Glasses hold approximately 12 fluid ounces when filled to the brim. Bottom of glass reads Libbey Duratuff. Glasses will be individually wrapped and carefully boxed to help prevent breakage.