Rotary die cutting involves crush-cutting material between the blades on a cylindrical die and an anvil, which is a smooth hard cylinder. Though sheets of material can be fed through a rotary die, it is more common to cut material including foam parts in continuous roll form. It is used to fashion soft to semi-rigid materials, typically in roll form into custom shapes and parts. Rotary cutting has a number of distinct advantages that includes the depth of cut can be controlled precisely between the anvil and the die which makes it ideal for 'kiss' cutting and results in long life and clean cuts for 'thru' cutting. The rotary method uses knife-edge cutting blades designed to cut a particular shape. A machine presses the die into the material to produce the desired shape. The blades can be designed to cut a diverse range of raw materials. Labels, envelops, folders, cartons and documents are just a few items produced using the rotary die cutting process. It is extensively used in manufacturing industry and stand-alone die cutting firms. Material can be processed at high rates of speed. The limiting factor for productivity rarely lies in the cutting. It is usually the material handling, the size of the rolls, or other in-line processes that limits the process speed.