The mark sometimes seen on the base of the ware is from the manufacturing process. When the gob of hot glass is cut, the scissors leave a mark or a ‘line’ in the glass. As the glass cools rapidly, the mark hardens in the glass. This mark can be seen with the naked eye and sometimes felt with the finger. This is no way detracts from the performance of the ware, nor will it cause breakage.
VISIONS cookware is made of a highly heat resistant and durable glass material. It is very heat resistant and does not stain or retain odors as will plastic cookware. It is easy to clean and is harmless to health.
All VISIONS cookware can be used in conventional, convection, toaster and microwave ovens; gas and electric stovetop; in the refrigerator, freezer and dishwasher. For use in freezer, please use with caution as liquid expansion may cause possible pressure for glass to break.
Generally you should not use any chipped, cracked or broken glass product. The glass item can be very risky. Hence, do not use damaged VISIONS cookware or glass cover.
To loosen cooked-on food, soak cookware in mild warm soapy water or in vinegar and water mix with the ratio of 1:3 for long hours. VISIONS cookware retains heat so well, you can use a lower heat setting than normal and save on energy. This also helps prevent sticking or burning of food. Use only plastic or nylon cleaning pads, as metal harsh scouring pads can leave grey marks on VISIONS cookware surface.