The practice of sandwiching a thin film of plastic between two pieces of glass creates laminated glass, a common component both safety and security glazing. The plastic sheeting, usually made of polyvinyl butryl (PVB), holds the glass together when it is broken, preventing the glass from flying and causing injuries or damage. Laminated glass consists of at least two pieces of glass and one plastic interlayer, though it can be made with more layers if needed.