Milk glass in the context of Opacifier

Venetian glass (Italian: vetro veneziano) is glassware made in Venice, typically on the island of Murano near the city. Traditionally it is made with a soda–lime "metal" and is typically elaborately decorated, with various "hot" glass-forming techniques, as well as gilding, enamel, or engraving. Production has been concentrated on the Venetian island of Murano since the 13th century. Today Murano is known for its art glass, but it has a long history of innovations in glassmaking in addition to its artistic fame—and was Europe's major center for luxury glass from the High Middle Ages to the Italian Renaissance. During the 15th century, Murano glassmakers created cristallo—which was almost transparent and considered the finest glass in the world. Murano glassmakers also developed a white-colored glass (milk glass called lattimo) that looked like porcelain. They later became Europe's finest makers of mirrors.

During the Early Middle Ages, Venice was originally controlled by the Eastern Roman Empire before eventually becoming an independent city state. It flourished as a trading center and seaport in the High Middle Ages. Its connections with the Middle East helped its glassmakers gain additional skills, as glassmaking was more advanced in areas such as Syria and Egypt. Although Venetian glassmaking in factories existed as far back as the eighth century, it became concentrated in Murano by law beginning in 1291, in part because glass factories often caught fire, and moving all of them to one island removed much of the possibility of a major fire disaster for the rest of the city. Another reason for moving the glassmakers to Murano was that Venetian glassmakers developed secret recipes and methods for making glass, and the concentration of Venice's glassmaking on the island of Murano enabled better control of those secrets.