A common issue when using custom proof standards is high dE readings during verification.
It may be the case that everything is working as expected except for selected standards – for example ISO Coated v2 (39L) passes with no issue, the calibration is good and the environment is okay, but a particular proof standard persistently fails verification.
Why does this happen?
This problem can occur when the XML for ProofControl has been generated from target values that no longer reflect the way the profile is printing. The profile may have color corrections made to it, or it was not iterated close to the target values.
How can I make my custom proof standard pass again?
The target values inside your MX4 must be reset and recalculated before generating a new XML file.
- Go to Tools then Reset Target Values.
- Go to Measure then Estimate Target Values from CMYK.
- If the gamut is missing from the MX4, a warning will appear. Go to the Common tab and check in the bottom right-hand corner. Separation should be set to 'Inkjet' or 'Multicolor Inkjet', and the gamut path should be linked to the gamut file used by the calibration.
- During the calculation, tick 'Use Dot Gain' but leave the other checkbox unticked.
- Save the profile (give a different name if desired).
- In ColorProof:
- Go to the Database tab then Proof Standards.
- Open the properties of the relevant Proof Standard, or create a new one.
- Under Colour Management, link to the newly adjusted MX4 file (if changed).
- Under Proof Verification, click the Bin button (if applicable) and then the Green Tick (from Contone MX4) button.
This limitation is now also addressed with the new 'from Measured jobs' feature in ColorProof 5.9.1. Please find the details from the SupportNews below.
Create print standard based on inline measured strips
When working with visually corrected MX4 and MX5 profiles as company standard and/or profiles with target values which are beyond the reachable gamut, ProofControl Inline validation often fails.
ColorProof 5.9.1 offers the possibility to create a reachable print standard for these profiles. Print standards can be calculated by loading the values of one or multiple measured jobs. Based on the measured values, the ProofStandard contains a reference with ProofControl Inline target values which can be reached by the printer.
Tip 1: Set the filter manually to the measurement condition, which has been used to measure the reference job. This can be looked up in the history job. History > Open Job > Info > Measurement device info > Filter.
Tip 2: Change to ISO 12647-7:2016 if required. The option will change the color difference formula to dE2000 and the tolerances according to the ISO 12647-7:2016 norm. \
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