In the late 15th century a В«milkyВ» opaque white glass, known as lattimo, was developed by the Venetians. It resembled the highly coveted porcelain imported from China and became popular during the 17th and 18th centuries. The technique had spread to Bohemia by the 18th century, where it was known as Milchglas. Bohemian glassmakers also produced innovative colored art glass, most notably a deep, strong blue glass created by adding cobalt oxide to the glass mix. As with Milchglas, this provided a perfect foil for colored enamels.