Roll-to-roll processing,

Roll-to-roll processing, also known as 'web' processing, is the process of creating electronic devices on a roll of flexible plastic or metal foil. Large circuits made with thin-film transistors and other devices can be easily patterned onto these large substrates, which can be up to a few metres wide and 50 km long. Some of the devices can be patterned directly, much like an inkjet printer deposits ink. For most semiconductors, however, the devices must be patterened using photolithography techniques.