This pair of vases is distinguished by the material used for its body; porcelain is usually preferred for its cobalt-blue, 'royal blue' or 'gros bleu' finish, particularly at the Sèvres factory. The crystal craze spread to France around 1770, when the number of factories increased significantly. Construction of the Royal Foundry near the Montcenis coal mine began in 1781, and in 1787 the Manufacture des Cristaux de la Reine, established in Sèvres, was transferred to the town of Le Creusot. A number of blue glass pieces, sometimes identified as coming from Le Creusot, some faceted, with Louis XVI gilt bronze mounts, were sold at public auction (Sotheby's, Paris, Un Hommage au XVIIIe siècle, November 30, 2011, lot 75; Christie's, New York, May 17 and 18, 2005, lot 440). Russian pieces also reflect this taste for tinted glassware, produced by La Manufacture Impériale de verre in St. Petersburg.