France | Flame polishing gives glass an especially smooth surface. This is particularly important in the flasks and jars produced by the glass manufacturer Zignago Vetro Brosse. The plant in Vieux-Rouen-sur-Bresle in Normandy’s “glass valley” specializes in high-quality containers for fine perfumes and cosmetics. Oxygen from Messer helps to optimize the process there. During flame polishing, a very thin layer is fused to the glass surface of the finished container. As it cures, changes in surface tension give the glass its silky smoothness and fine luster. Mechanical and chemical polishing (acid treatment) are standard methods that are more costly and also more detrimental to the environment. Zignago Vetro Brosse, a company of the Italian group Zignago Vetro, has been manufacturing glass for 150 years.