Using Control Strips

Which kind of control strips are supported in GMG ColorProof?

Control strips defined by an official print standard, CMYK only: Available for factory-default and custom proof standards, and GMG OpenColor proof standards
Control strips defined by an official print standard, CMYK and spot colors: Available for GMG OpenColor proof standards
GMG spot color control strips: Dynamically generated from the spot color channels used in the image
GMG OpenColor control strips: Dynamically generated from the color channels (GMG OpenColor inks) used in the image
GMG Calibration Control Strip: Used for checking if the printer still works in the tolerances or needs to be recalibrated

All four CMYK channels need to be available.

When using a multicolor ICC profile, you can verify the CMYK part (if available) of the profile and single spot colors, but not the overprinting behavior of the spot colors.

What do I need to do?

If you are using a factory-default GMG proof standard, you just need to select an image or job control strip in the job and GMG ColorProof will use the correct target values as defined in the proof standard out of the box.

Likewise, if you are using a GMG OpenColor proof standard, GMG ColorProof will take the target values from the proof profile and you do not need to worry about it.

If you want to use stricter tolerances or verify against a custom print standard, however, you need to take care that appropriate target values and tolerances are defined as explained in the following.

Customize tolerances and target values

You want to use stricter tolerances? You can create a custom print standard in GMG ColorProof and then edit the tolerances in GMG ProofControl.

You want to use custom target values? You can create a custom print standard either from an official print standard or from the proof profile and then edit the target values (and tolerances) in GMG ProofControl.

Proof verification will fail if target values in the print standard XML do not match with the target values in the proof profile.

The procedure is slightly different whether you are using a proof profile from GMG OpenColor or not as shown in the following table.

Proof profile	How it works
Without GMG OpenColor	Target values and tolerances for CMYK are always taken from a GMG ProofControl Print Standard XML file linked to the proof standard, which needs to match the selected control strip. If there are no target values for the selected control strip, proof verification will not be possible. Target values for spot colors will be extracted from the spot color set (db3). You have multiple options to create your own custom GMG ProofControl Print Standard XML file. Please follow the link for more information: Adding a Custom GMG ProofControl Standard GMG ColorProof will use the Evaluation rules defined in the GMG ProofControl Print Standard, i.e. the delta E tolerances for the substrate, CMYK, and spot colors. Please see here how to customize the tolerances in GMG ProofControl: Creating a Custom Print Standard
With GMG OpenColor, custom proof standard (static and dynamic profiling)	You have the option to define the target values for CMYK and spot colors by linking GMG ProofControl Print Standard XML files to the proof standard. If there are no CMYK target values for the selected control strip in the GMG ProofControl Print Standard XML files, proof verification will not be possible. Proof verification will fail if target values in the print standard XML do not match with the target values in the proof profile. To ensure that they match, you can create the GMG ProofControl Print Standard XML file from the proof profile as explained in the following. You can create a custom GMG ProofControl Print Standard XML file for a static proof standard with the action Generate From Proof Standard > From Contone MXN. For a dynamic proof standard, this action is not available. However, you can create a static proof standard with an MXN profile, create the GMG ProofControl Print Standard XML file from this proof standard, and then link it to a dynamic proof standard. Please follow the link for more information: How to generate a custom GMG ProofControl standard from the profile in GMG ColorProof (Generate from Proof Standard) Please see here how to customize the tolerances in GMG ProofControl: Creating a Custom Print Standard If you do not link any Print Standard XML file to the proof standard, target values will be calculated from the proof profile and the tolerances from the Default Control Strip will be used. If CMYK is not included in the proof profile, proof verification will not be possible. When using dynamic profiling, the proof profile requested from GMG OpenColor will include only the colors channels that are available in the input document. In this case, the document needs to include CMYK color channels.

Proof profile

How it works

Without GMG OpenColor

Target values and tolerances for CMYK are always taken from a GMG ProofControl Print Standard XML file linked to the proof standard, which needs to match the selected control strip. If there are no target values for the selected control strip, proof verification will not be possible. Target values for spot colors will be extracted from the spot color set (db3).

You have multiple options to create your own custom GMG ProofControl Print Standard XML file. Please follow the link for more information: Adding a Custom GMG ProofControl Standard

GMG ColorProof will use the Evaluation rules defined in the GMG ProofControl Print Standard, i.e. the delta E tolerances for the substrate, CMYK, and spot colors. Please see here how to customize the tolerances in GMG ProofControl: Creating a Custom Print Standard

With GMG OpenColor, custom proof standard (static and dynamic profiling)

You have the option to define the target values for CMYK and spot colors by linking GMG ProofControl Print Standard XML files to the proof standard.

If there are no CMYK target values for the selected control strip in the GMG ProofControl Print Standard XML files, proof verification will not be possible.

Proof verification will fail if target values in the print standard XML do not match with the target values in the proof profile. To ensure that they match, you can create the GMG ProofControl Print Standard XML file from the proof profile as explained in the following.

You can create a custom GMG ProofControl Print Standard XML file for a static proof standard with the action Generate From Proof Standard > From Contone MXN. For a dynamic proof standard, this action is not available. However, you can create a static proof standard with an MXN profile, create the GMG ProofControl Print Standard XML file from this proof standard, and then link it to a dynamic proof standard. Please follow the link for more information: How to generate a custom GMG ProofControl standard from the profile in GMG ColorProof (Generate from Proof Standard)

Please see here how to customize the tolerances in GMG ProofControl: Creating a Custom Print Standard

If you do not link any Print Standard XML file to the proof standard, target values will be calculated from the proof profile and the tolerances from the Default Control Strip will be used.

If CMYK is not included in the proof profile, proof verification will not be possible. When using dynamic profiling, the proof profile requested from GMG OpenColor will include only the colors channels that are available in the input document. In this case, the document needs to include CMYK color channels.

Please note that job control strips cannot be used for GMG OpenColor jobs.