Fragment of a Roman window glass plate dated to 1st to 4th century A.D.
Flat glass, sheet glass, glass pane, or plate glass is a type of glass, initially produced in plane form, commonly used for windows, glass doors, transparent walls, and windshields. For modern architectural and automotive applications, the flat glass is sometimes bent after production of the plane sheet. Flat glass stands in contrast to container glass (used for bottles, jars, cups) and fiberglass (used for thermal insulation and optical communication). Most flat glass is soda-lime glass, produced by the float glass process. Other processes for making flat glass include: