CTP (Computer to Plate) is a streamlined process of print production. Streamlined in that takes a finalized file from a computer and outputs it directly to a plate. The plates are made from a variety of materials ranging from aluminum to polyester. Once the plate is imaged, it can be used on the press. In the old CTF process the file was sent from the computer to a film processor, then the film image was transferred to the photographic plate so the plate could be used on the press. http://www.ecoographixsolution.com/printing-plate-machine/