Prepress is the term used in the printing and publishing industries for the processes and procedures that occur between the creation of a print layout and the final printing. The prepress procedure includes the manufacturing of a printing plate, image carrier or form, ready for mounting on an offset printing press. In today’s prepress shops, the customer mostly delivers their image electronically, either a PDF file or application files created by programs such as Adobe InDesign.
CTP is an imaging technology used in modern printing processes. In this technology an image created in a Desktop Publishing (DTP) application is output directly to a printing plate. The plates are exposed to ultraviolet light lamps and laser diodes which form the image in the plate.
For every color a different plate is manufactured because every color contains a slightly different image. All plates/colors combined make a full-color image.