implements. All opaline glass is hand-blown and has a rough or polished pontil on the bottom. There are no seams and no machine engraving, and most opaline glass is not branded or signed. Many pieces of opaline glass are decorated with gilding. Some with handpainted flowers or birds. Several have bronze ormolu mounts, rims, hinges or holders. Later opaline glass The French factory Portieux Vallérysthal in 1930 has put opal glass objects on the market in a particular blue-azure color. Some pieces have decorations in pure gold or polychrome enamels and are sometimes equipped with supports or hinges in gilded bronze (sets of plates, cruets, sets of glasses and cups, boxes, lamps, flacons, chandeliers). The blue-blue color of the glass is inspired by that of the American robin's egg. In the late 20th century the venetian master glassmaker Vincenzo Nason, began producing a similar type of glass, labelled 'Veritable Opaline de Murano'. Further reading Glass art Glass compositions Spoken articles