Vitreous enamel, used to decorate and protect pottery, metals, etc., is?
Vitreous enamel Enamelled glass is also called "painted", and overglaze decoration to pottery is often called enamelling. Enamelling is an old and widely adopted technology, for most of its history mainly used in jewelry and decorative art. Since the 19th century, enamels have also been applied to many consumer objects, such as some cooking vessels, steel sinks, enamel bathtubs, and stone countertops. It has also been used on some appliances, such as dishwashers, laundry machines, and refrigerators, and on marker boards and signage. The term "enamel" has also sometimes been applied to industrial materials other than vitreous enamel, such as "enamel" paint
Vitreous enamel steel plates. Enamel was first applied commercially to sheet iron and steel in Austria and Germany in about 1850. Industrialization increased as the purity of raw materials increased and costs decreased. The wet application process started with the discovery of the use of clay to suspend frit in water. Developments that followed during the 20th century include enamelling-grade steel, cleaned-only surface preparation, automation, and ongoing improvements in efficiency, performance, and quality. Vitreous enamel can be applied to most metals. Most modern industrial enamel is applied to steel in which the carbon content is controlled to prevent unwanted reactions at the