borosilicate glass it appears as though the liquid is 'floating' within the glass. They will not sweat when filled with a cold beverage, so you will not have to use a coaster. The double wall creates a thermal effect, helping to keep your cold drinks cold and your hot drinks hot for longer periods of time. These mouth blown glasses are an exciting product for any home, restaurant, or cafe and they are a definite conversation piece. Bodum’s insulated glassware is made from durable Borosilicate glass. Borosilicate glass is a strong heat-resistant glass traditionally used to make scientific lab glass. Stronger than traditional “soda-lime” glass, borosilicate can be used for everything from drinkware to cookware.