Schott Zwiesel Tritan Crystal Glass. Since 1872, we have been dedicated to serving the world’s guests and finest hosts. ZWIESEL GLAS has never just been about glass, but has always echoed the possibilities inherent in glass. We strive to create unique products at the highest level of manufacturing, skill, and craftsmanship that offer extraordinary experiences of enjoyment and community. The sound of a toast with a ZWIESEL glass is the unmistakable sound of authentic hospitality. Our machine-made series, SCHOTT ZWIESEL, not only impress with their high brilliance and special resistance to breakage and dishwashing, but are also characterized by their sustainability. Only regional and tested materials are used for production which ensures 30% less energy consumption and significantly less carbon dioxide and nitrogen emissions during production.