The revolutionary material is a special three-layer glass laminate called Vitrelle Glass, originally planned as a material for American TV screens.It is characterized by: RESISTANCE,COMFORT,EFFIZIENZ: The material is resistant to breakage, chipping, scratches and discoloration, it is microwave, oven, refrigerator, freezer and dishwasher safe. Crockery can be stacked to save space. Color: Black & White. The cups are not break-proof!