BOPP (Bi-axially Oriented Polypropylene): When polypropylene film is extruded and stretched in both the machine direction and across machine direction it is called bi-axially oriented polypropylene. Bi-axial orientation increases strength and clarity. BOPP is widely used as a packaging material for packaging products such as snack foods, fresh produce and confectionery. It is easy to coat, print and laminate to give the required appearance and properties for use as a packaging material. This process is normally called converting. It is normally produced in large rolls which are slit on slitting machines into smaller rolls for use on packaging machines.