Designed with your favorite sparkling wines in mind, the Riedels invented a unique way to extend the bubble action. At the base of these elegantly curved Champagne glasses lies the secret; a tiny glass dot formation in the very bottom of the bowls produce a "time-release" effect, keeping your bubbly - bubbly. Introduced in 1986, the Riedel Vinum line was the first machine-made series of glasses in history to be based exclusively on the characteristics of grape varietals. The Vinum series has had a strong and permanent impact on the wine glass culture around the globe. These glasses have proven to consumers and restauranteurs that the pleasure of consuming wines starts with the glass. Developed by 10th generation Georg Riedel on the principle that the contents commands the shape, Vinum is great for everyday use. These glasses are made with over 24% lead crystal.