How do you figure out how many plates or cylinders will be needed for a print job?
Answered by Stephen Beals, Digital Pre-Press manager and industry writer
Question:
How do you figure out how many plates or cylinders will be needed for a print job?
T.V.
Answer:
The number of plates and cylinders needed to produce a printed job are a factor of how many ink colors and special effects are required.
For example, a job that is black and one spot color will require two plates. A process color (CMYK) job requires four plates.
However, if you are applying a spot varnish, an additional spot color, perforations or other additional effects, each of those will require an additional plate and use an additional cylinder on the press.
Of course there are some options on how effects are applied. Numbering, perforating slitting and other effects are sometimes done offline. Many modern large offset presses have coating units that can apply an overall varnish and in some cases a spot varnish without using an additional cylinder of the press. An overall coating can be applied without an additional plate on presses equipped with a coater and dryer, though you will still have to pay extra for the coating.
If you are running a process job with a spot metallic ink a perforation and an overall coating on a six color press with a coater, it could all be done in one pass. There would be four process color plates, one metallic color plate and one perforation plate. Then the whole thing would run through the coater at the end of the press.
On the other hand, perforations, scoring, numbering, laminating and other effects are often done off press for several reasons. It might be that the grain of the stock makes it easier or gives better results if the work is done offline on a press designed for that purpose. Some types of metallic inks or other special effects can require drying time before the effect can be applied.
Other factors that can change the number of plates or cylinders needed:
• Some PMS colors are simply impossible to match using CMYK inks, requiring a separate plate for a spot color.
• Some very large solids may require double hits of ink
• Some effects can require a special ink or coating to be laid down on the first pass before the effect is laid down on a second pass.
• In some cases the layout of a job will require that one color be applied with two separate plates. An example might be when two large solids need to be printed that would cause ghosting if they were printed on the same plate.
• Remember that if you have a gloss varnish and a dull varnish on the same job, that will require two different varnish plates.
• It is sometimes possible to eliminate an extra plate (for example, double hitting a black solid) by using tints of the other three process colors to create a "rich black" to enhance the black solid. It works for many solid colors, too.
Stephen Beals is a digital pre-press manager and has been writing for major print publications for many years. He is the author of A Practical Primer for Painless Print Production. He can be reached at stephenbeals@mac.com.
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