Verifying Spot Colors

If you want to know how well spot colors printed in an image match the reference values, you can add a spot color control strip to your image in GMG ColorProof (> Image Control Strips).

With an integrated ILS30 measuring device and a GMG ProofControl Inline license, all patches are automatically measured and a verification label is printed on the proof.

GMG OpenColor spot colors are validated by comparing the measured values against the Lab target values from the multicolor profile. In both cases, the Delta E values are printed in a label, showing you which spot colors can be reproduced by your printer-medium combination and which colors are out-of-gamut. You can optionally define tolerances for a pass/fail verification of the spot colors.

  • Fogra MediaWedge Multicolor 5C, 6C, 7C, 8C: Verification is supported when using a printer with an integrated ILS30 measuring device and a GMG OpenColor proof profile or proof standard.
  • IDEAlliance ECG Digital Control Strip 2019: For CMYK OGV printing processes. Verification is supported when using a printer with an integrated ILS30 measuring device and a GMG OpenColor proof profile or proof standard.
  • The GMG Spot Color Strip - Full Tone uses only 100% full tone patches and has a fixed size of 10 patches. GMG ColorProof assigns the first 10 spot color channels found in the image to the 10 channels of the control strip. The strip contains one full-tone patch (100% fulcrum) for each spot. If the image contains more than 10 spot colors, exceeding spots will be ignored.
  • The GMG OpenColor Control Strip uses full tone patches plus additional spot color tints for the verification process. Only spot color tints with corresponding measurements in the GMG OpenColor database can be validated. Verification is supported when using a printer with an integrated ILS30 measuring device and a GMG OpenColor proof profile or proof standard.
  1. On the navigation panel on the left of the main program window, click System.
  2. Click the GMG ProofControl Inline tab.
  3. In the Proofer Supporting Direct Label Printing group, from the Print Label Automatically on Proofer list, select Always or Only if Verification Passed to directly print the label on the proof.
  4. Create a job for an image with spot colors.
  5. Image > Label/Strips/Marks > Image Control Strips: Select the option Control Strip 1 (or 2).
  6. From the Measuring Device list, select the integrated measuring device you are using.
  7. Under Control Strip Type, select a spot color control strip and determine where to place the strip.
  8. Print the job.
    GMG ColorProof prints the job with the control strip. The color patches will be automatically measured by the integrated measuring device. The print medium will be rolled back and the GMG ProofControl Inline label will be printed next to the control strip.

Verification of spot color control strips in GMG ProofControl is supported only for the X-Rite i1 measuring device and only for spot colors from a db3 spot color set, not for spot colors from GMG OpenColor.

  1. Start GMG ProofControl.
  2. Under Options > ColorProof Connection, select the option Use Automated Measurement Import. Browse your folders and select the folder where the measurement jobs are saved (default path: <installation path>\GMG\ColorProof05\ProofControl Output).
  3. Create a job in GMG ColorProof using an image with spot colors.
  4. Image > Label/Strips/Marks > Image Control Strips: Select the option Control Strip 1 (or 2).
  5. From the Measuring Device list, select i1.
  6. Under Control Strip Type, select GMG Spot Color Control Strip - Full Tone and determine where to place the strip.
  7. Print the job.
    GMG ColorProof prints the job with the control strip. The job is automatically exported to the GMG ProofControl Hotfolder defined in step 2 and displayed in the main view in the Jobs list.
  8. Switch to GMG ProofControl and select the measurement job in the Jobs list.
  9. Measure the strip with an i1.
  10. Click on the Print Label button on the toolbar to print a label with the verification results.