Proof and Print Matching

A common question is why doesn't my proof match the print, or why doesn't my proof match another proof? There are many reasons why you may be seeing a visual difference between your proof and print, or between two proofs. This article highlights some areas you can check on the proofing side.

It is important to remember that the tolerances in GMG ColorProof are much closer than any kind of differences you would see on a press run.

If you require further assistance after completing the below checklist, please feel free to get in touch with us.

• Verification
  
  • Does the control strip pass within tolerances in GMG ProofControl or ProofControl Inline? Otherwise, you cannot be sure your printer was printing correctly at the time the proof was printed.
• Image File
  • Is the image file completely identical? It's surprising how often different revisions of files are printed, often with different levels of colour management performed on them. Ensure the image is 100% identical on all proofs and prints.
• Media
  • Check that the media used is identical on both sides. In particular, look out for the watermark/backstamp on the back of the GMG media to make sure it official.
• Versions
  • Ensure the ColorProof and Proof Standard versions are identical. Profiles and calibration sets may be improved in later versions, so it is important that the version is the same.
• Calibration
  • Is the printer model and calibration mode used the same? Due to different printing technologies, there may be some visual differences if the proofing condition is not completely identical.
• Reset Calibration
  • If you are confident that the proofing condition is completely identical, try to reset your calibration. It could be that the printer calibrated with a nozzle blockage, which then recovered. This is especially the case if a physical nozzle check pattern is not printed directly before every calibration. If this happens then the calibration is ‘skewed’, affecting all proofs printed through it. Even though the calibration is passing, the result may have been influenced by a bad nozzle. Resetting the calibration (by right-clicking on the calibration set name and choosing ‘Reset calibration’) brings the printer back to a blank starting point, removing any possible skewed data.
• Spot Colors
  • If you see a difference in spot colors, ensure you are using a spot color control strip. This can be enabled your job or workflow properties, as a second strip. It will read each spot color on the proof and give you a dE as to how close to the target Lab it is printing. Unfortunately, Pantone books are notoriously inaccurate - they often don't match up to other Pantone swatch books, and measuring these swatches with a calibrated i1Pro2 invariably gives different readings to the defined target Lab.