A Contract Proof is a color-consistent and legally binding proof according to ISO 12647-7. The Contract Proof is currently the highest proof standard with the narrowest tolerances and is therefore considered a “contract”, i.e. a contract between the proof maker and the printing house.
The quality and performance of a proofing system can be checked and issued by Fogra, for example, with the “Contract Proof Creation” certificate. Companies that are certified by Fogra for the creation of contract proofs may use the FograCert logo. Using the certification number, it is easy to check on the Fogra website for which Proof Standard the certificate was issued and whether it is valid.
Since the certificate is associated with high costs and expires after only one year and must be recertified, many companies shy away from the costs and unfortunately advertise with certificates that are many years old.
A Digital Proof (Contract Proof) is an ISO certified test equipment for the graphics industry. A digital proof simulates the colour of offset printing or gravure printing colour accurate binding within the tight tolerances of ISO 12647-7. Today, a digital proof is processed via a RIP and then produced with pigment inkjet printers on special proofing papers.
The proof data is converted to colour separations, then reassembled into a composite image to simulate overprinting and trapping correctly. The data is then passed as a composite image to a usually more than 8-colour inkjet printer, which prints the data. In addition to the proof data, a digital proof must carry a Mediawedge by UGRA / FOGRA or IDEAlliance to be legally binding. Thanks to the standardized mediawedge, the print shop is able to check the proof for correctness. Since many printers don’t have the neccessary metrology at hand, digital proofs are often directly provided with a test report, which documents the accuracy of the measured values of the media wedge directly on the proof.
Older proofing methods as chromalin or Kodak Approval etc. are today hardly any more found in the market.
In the ISO 12647 “Contact Proofs” (ISO 12647-7) are the highest standard of proofs, but the term “Validation Prints” (ISO 12647-8) is also defined. A “Validation Print” is distinguished in that it is less accurate in colour, but therefore can also be produced on laser printers. Compared to the contract proof, a Validation Print has higher colour variations and is NOT automatically legally binding – only after prior consultation. A real “proof”, ie a real contract proof according to ISO 12647-7 is currently not only the most colour accurate and best option, but also the only legally binding proof.
PSO stands for “ProcessStandard Offset Printing”, a standard that was developed by Fogra and the German Printing and Media Industry together. The ProcessStandard Offset Printing is a set of standards for offset printing. With test equipment and control by measurments as described in the PSO, the printing process of the data delivery and data preparation on the platemaking is monitored, controlled and checked.
The following standards are summarized in PSO – “ProcessStandard Offset Printing:
ISO 00005-4: Optical density
ISO 02846-1: Printing inks
ISO 03664: Standard Lighting
ISO 12218: Platesetting analog
ISO 12641: Scanner Testchart
ISO 12642: Output test charts
ISO 12646: Monitors
ISO 12647-2: standard pressure
ISO 12647-7: Digital Proof
ISO 13655: Spectral color measurement
ISO 13656: Densitometric and colorimetric measurement
ISO 14981: Densitometer