CTP Machines

What is CTP?

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. In the CTP process, the film step and its associated chemicals and bio hazard are completely eliminated.

When you remove the film step and the associated chemicals, you are saving on film and chemical costs, the chemical smell is greatly reduced, and you are producing high quality plates at a faster rate. Since we all know that time = money, what this means is that with each plate you produce, you are saving on the equipment, labor and supply costs that your company has when it produces a print piece for a client.

Because CTP Plate Making Machines use a new and straightforward technology, it stands to reason that there would be a variety of ways to implement it. This variety has emerged in the multiple technologies available for CTP, which are Violet, Thermal, Ink Jet and Poly Plate.

What's the difference in the technologies?

Since violet and thermal are currently the major players in the CTP market I will focus primarily on them. Both Violet and Thermal use laser diodes to transfer the image onto the plate. The difference in the two types of lasers are the color of the laser and the wavelength of the light they emit. Violet has less lasers than a thermal machine and because of this has a lower acquisition cost. If you compare the quality of a violet and a thermal system, you would see that the thermal system can produce better quality than a violet system can. A thermal system can produce line screens exceeding 300lpi, whereas a violet system maxes out at 300lpi. That said, anything over 300lpi is actually overkill on the vast majority of projects.

Due to the fewer number of lasers in the machine, violet plates are light sensitive. This requires either a safelight environment (typically a yellow light) or the auto-load option that most manufacturers have can be used. Conversely, thermal plates can be used in normal daylight conditions.

As to speed of production, violet produces plates faster, but thermal machine manufacturers are trying to cut the time gap with their newer technology. It seems odd though that speed would be a major factor here because compared to the old CTF process, thermal is still much faster.

Except for CTP, there are some other print machines may used like Label Printing and Cutting Machines, Digital Printing and Finishing Machines. They have to work with some Other Printing Materials such as Laser Imagesetters, Printing Plates including Offset Printing CTP Plates and Other Printing Plates, Printing Consumables, etc.