CTP PLATE ADVANTAGES AND DISADVANTAGES

　　Advantages

　　CTP has several advantages over conventional platemaking. In CTP, one generation (transfer of film image to the printing plate) is removed from the printing process (eliminating the need for film and related developer chemicals), increasing sharpness and detail. CTP avoids potential losses in quality that may occur during film processing, including scratches in the film, and variations in the exposure. An imagesetter usually has an accuracy rate of ±2%.[2] Plates are produced in less time, are more consistent, and at a lower cost. CTP can also improve registration and image-to-edge repeatability over traditional methods. More recent advancements in CTP plate technology made by companies such as Dupont and PlateCrafters have further widened the gap with analog plates, allowing for very fine vignettes and minimal dot gain on press.

　　In CTP, the media is registered (held in precise position) in the platesetter during imaging, and does not rely on a separately-aligned pin grid, as is the case with film. Defects due to dust, scratches or other artifacts are minimized.

　　CTP systems can significantly increase plate production outputs. Platesetters for newspaper production can output up to 300 12-inch (300 mm) plates per hour at 1,270 dpi (dots per inch), whilst for commercial applications a CTP system could output 60 B1 plates at 2,400 dpi for higher screen rulings.

　　Small portrait presses that typically create 1 or 2 color output can use anything from a standard laser printer, for low quality/low volume, up to a higher-end dedicated platesetter for higher quality and volume.

　　Disadvantages

　　CTP is restricted to digital format. CTP productions require that the basis for the printed matter as well as the imposition be digital.

　　In CTP, if for some reason a plate is damaged, if an error occurs when it's ripped or if something has to be corrected after the plate is exposed, a completely new, imposed plate must be created.