A new technique called Bronzite decoration was developed shortly before 1910. It involved coating the entire surface of a glass with a black or brown metallic paste and re-firing the vessel. Then, the desired ornament was covered with an asphalt lacquer and the uncovered areas were etched away with acid. The acid etching removed the unwanted coating, created a matte surface, and left behind the desired design. See this champagne cup and other Bronzite decorated glass, in “Glass of the Architects: Vienna, 1900–1937,” a cooperation of the MAK and LE STANZE DEL VETRO, only on view at CMoG through January 7!
Champagne Cup, “Schwarzbronzit Var. C” Series, designed 1911, manufactured after 1912. Designed by Josef Hoffmann (Austrian, 1870–1956); manufactured by Wiener Werkstätte, J. & L. Lobmeyr, and Meyr’s Neffe. Mold-blown, bronzite-coated, and etched glass. H. 11.8 cm, Diam. 10.3 cm. MAK – Austrian Museum of Applied Arts / Contemporary Art (WI 1675). © Nathan Murrell.