Coffee cup and saucer set produced in France circa late 1950s in a beautiful Art Deco style. A few French glasswork companies in the 1950s – 1960s were manufacturing this delicate *opalescent, light blue milk glass cups and saucers, following from the golden era of art deco glass production synonymous with the 1920s and 1930s. Reputed French makers Lalique, Portieux Vallerysthal and Sabino, and Jobling from England are, to this day, famous for their opalescent art deco glass creations. Opalescent glass has also been produced in various other countries including Italy and Czechoslovakia, where other fine examples have been found.
One way of creating opalescent glass is the slow cooling of the thicker areas of the glass, resulting in crystallisation. Another method is used in hand blown glass, using two layers of glass, with the outer layer containing chemicals which react to heat to cause opalescence. Opalescent glass can also be created by reheating certain areas as they begin to cool, again with the use of heat sensitive chemicals.
* Opalescent glass is a general term for clear or coloured glass with a milky white opaque or translucent effect often to either the rim (such as Davidson's Pearline range) or centre of the glass item.
