Digital proofs (correct: contract proofs) are an ISO-certified test equipment for the graphic arts industry. Digital proofs simulate the colourfulness of offset or gravure printing in a colour and legally binding manner within the narrow tolerances of ISO 12647-7. Today, they are almost exclusively calculated using a RIP and then produced with inkjet printers on special proof papers.
The proof data is converted into separations, then reassembled into a composite image to correctly simulate overprinting and trapping. The data is then transferred as a newly created composite image to an inkjet printer, usually with more than 8 colours, which prints the data. In addition to the print data, digital proofs must also carry a UGRA/Fogra media wedge in order to be colour-consistent and legally binding. Thanks to the standardised wedge, the printer is able to check the proof for correctness. Since many printing houses do not have this measuring technique at hand, the proof is often provided directly with a test report that shows the correctness of the measured values of the media wedge directly on the proof.
Earlier methods such as Chromalin etc. are no longer available on the market today.
ISO 12647 defines the highest standard of contract proofs, or “proofs” (ISO 12647-7), as well as the term “validation prints” (ISO 12647-8). Validation Prints are characterised by the fact that although they are less accurate in colour, they can also be produced on laser printers. Compared to contract proofs, however, they accept much higher colour deviations and are only legally binding after prior consultation. Real “proofs”, i.e. true contract proofs according to ISO 12647-7 are currently not only by far the best variant in terms of colour but also the only legally binding proofs.
The company NEC is currently considered one of the most competent manufacturers of proof monitors. The NEC Spectraview series in particular offers sophisticated monitor technology and clever software solutions for high-quality colour processing.
The NEC SpectraView Reference series consists of high-quality LCD monitors with 10-bit AH-IPS and GB-r LED backlighting for colour-critical applications. The numerous functions and advantages ensure the best possible picture quality and colour fidelity
Further information: http://www.nec-display-solutions.com/p/de/de/home.xhtml
The advantages of a softproof are obvious: It is fast, does not produce costs for paper and ink and is reliably reproduced with little effort. In addition, monitors have a very large colour space and can be quickly linearized and calibrated if necessary.
The disadvantages: Especially when controlling the print, a comparison of a paper proof to the final print is significantly easier than the comparison of a self-luminous image display with a passive illuminated paper. In addition, print control must be done under very bright light (2000 Lux) according to ProcessStandard Offset; for Softproofs on the other hand, the light must be darkened down to at least 700 Lux, because most soft proofing monitors are calibrated to dark 120 to 180 Candela, some monitors being capable of displaying 350 Candela, but these are not capable to display the entire ISOCoatedV2 gamut.
In the long term Softproofing will certainly be established, since the monitor technology is making great progress constantly. Currently, however, a simple hard copy proof is the common solution in controlling print colour.