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Technical acceptance of your Computer-to-Plate system
The current situation
The high investment costs of CtP systems can only be justified when they are able to offer trouble-free, economical and high quality production. For this to be so, all the components of these complex systems – plates, setter, processor, pre-heater (in some cases) and so on – must be optimally suited to each other. Achieving this is no simple task, especially if the system is not a complete solution from a single supplier or when some staff lack CtP experience.
Demands
When advising printers it often transpires that all that exists is a set of technical specifications with some performance data, but no overall concept. The imaging quality to be produced by the CtP system will therefore only be recorded on the basis of a job or a test forme from the system manufacturer and visually assessed using subjective criteria. In very few cases will it be measured. When, in the course of time, flaws arise in the transmission quality there is no clean, objective and quantitative documentation of the output standard, and clear evidence is then difficult if not impossible to obtain.
Technical acceptance of the CtP system
It therefore makes sense to arrange for a neutral body such as Fogra to carry out a technical acceptance of the CtP system that involves quantitative measurements of its performance. Following a start up phase after installation of around 2 to 3 weeks the actual technical condition is recorded. The settings are checked and, if necessary, optimized. Excellent imaging quality, which includes a high degree of register accuracy, is always of primary importance. The Fogra acceptance checks look first of all at focusing and spot size, followed by register checks, with and without plate changes. In order to ensure uniform image quality, it is important that the system is capable of achieving a high degree of consistency, both spatially and over time, across the entire tonal range. In addition, the tonal value transfer from data set to print must also be set so that standard data sets that comply with the offset printing process standard or the 2004 media standard can be directly output without further conversion. This does not apply to particular printing conditions such as fine screens, which continue to require pre-treatment.
Acceptance guidelines
At present there are no generally recognized guidelines for the technical acceptance of CtP systems but in the near future ones are expected to be published by the Bundesverband Druck und Medien e.V. That being said, the specifications and contractual assurances of the individual manufacturers are important. In so far as it is possible, these will be checked by Fogra during the acceptance. The purchaser should not acknowledge the fitness for use of the installation and issue its financial OK until receipt of the Fogra approval.
Your Fogra contacts
Contact Dipl.-Ing. [FH] Max Ondrusch [Tel. +49 89. 431 82 - 319] or Ulrich Schmitt [Tel. +49 89. 431 82 - 337], who would be delighted to draw up a proposal for you.
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