Print Buying Direct | Order Printing Online

Establishing a standard
In the offset print world, the BPIF has already recognised that this is making life difficult for its members and is working to take general quality assurance controls one step further.

The idea is to provide a certification procedure that accredits printing companies for compliance to ISO 12647. This is the international standard for Graphic Technology Process Control for the production of Half – tone Colour Separations, Proofs and Production Prints. You can tell it’s important because of all those capitals. It is divided into seven sections: one defines parameters and measuring methods and the rest are specific to different print processes (offset, newspapers, gravure, screen, flexo and proofing).

An eighth is under consideration, but there is so far no subsection for digital printing systems. These often have different print characteristics to any of the conventional processes. While it may be often desirable to match digital to something else sometimes that would artificially limit its quality potential. Another problem is that there are a lot of digital ‘marking engine’ technologies, each with their own characteristics, unlike say offset presses that all use broadly similar plates, blankets and have agreed standards for process ink colours.

Even so, elements of the ISO 12647 offset and proofing parts can apply o digital work. Paul Sherfield, principal consultant with the Missing Horse Consultancy group, explains: ‘ISO 12647-2 is the litho part of the standard, based on the colour gamuts available from litho presses, inks and papers. Digital printing devices, though still mainly CMYK, have differing, often bigger gamuts. The question is what standard or gamut to use? This must be dependent upon the purpose of the piece. In a mixed printing process campaign, the litho colour gamut will be the smallest, so the other processes used have to colour manage their output to ISO 12647-2. if only one form of digital printing is being used, say wide format inkjet, the maximum gamut of the device can be used to produces great results, but only if it starts from a good RGB image’.

To be continued…