G7 Master FAQ

As of July 15, 2016 the G7 Master program mandates the use of updated documents, procedures and targets when submitting for G7 Master Qualification. This FAQ contains answers to common questions about the revisions to the G7 Master program.

Q: What is SCCA?

A: SCCA stands for Substrate-Corrected Colorimetric Aims – a standard mathematical formula based on the human visual phenomenon of chromatic adaptation – that simulates how CIELAB aim values (or a whole characterization dataset, or a printed image) would appear on a substrate different from that on which it was originally printed. The value of SCCA in the G7 Master process is that it allows a print or proof made on a non-standard substrate to be judged for its “relative accuracy”, i.e. how it would appear to an observer in the absence of a comparison proof. This is why SCAA is also referred to as “substrate-relative”.

Q: When filling out the Submission form, what does Relative mean?

A: Relative is SCCA (Substrate-Corrected Colorimetric Aims) ON.

Q: When filling out the Submission form, what does Absolute mean?

A: Absolute is SCCA (Substrate-Corrected Colorimetric Aims) Off.

Q: Can a proof be submitted for G7 Grayscale or G7 Targeted compliance?

A: No. All G7 Master proof submissions are treated as “color-accurate” proofs and therefore must meet G7 Colorspace compliance, accurately simulating a specific CRPC or color space.

Q: Is Idealliance mandating M1 measurements?

A: No. Idealliance is not mandating M1 measurements. Regardless of the CRPC (Colorimetric Reference Print Condition) at which a submitted print sample is aimed, the applicant may specify that the sample is measured in M0, M1 or M2, with the following understandings:

  • G7 Grayscale is substrate-relative and therefore not dependent on the measurement mode. G7 Grayscale submissions may be measured in M0, M1 or M2.
  • GRACoL 2006 was based on M0 but can also be measured in M1 or M2 mode if submitted as a “relative” match, i.e. with SCCA On.
  • GRACoL 2013 and the other six CGATS.21 / ISO 15339 CRPCs are based on M1, but can also be measured in M0 or M2 mode if submitted with SCCA On.

Submissions that do not use SCCA will be measured in the M mode on which the target CRPC is based.

Q: Are we losing the ability to use older measurement devices? Is Idealliance mandating that I update to newer M1 measurement devices?

A: No. Idealliance will still accept uploaded data measured with any device, but the printed samples must be measurable on the devices available at RIT (see G7 website for the current list). There is no requirement for users or G7 Experts to upgrade to a new device. Keep in mind, however, that media with significant OBA (Optical Brightening Additive) content are best measured with newer M1 devices, if they will be viewed in newer, full-UV D50 viewing booths.

Q: Are custom test forms allowed?

A: Yes. You may change the supplied test forms in any way you like so long as you include the current QR code and the following:

  • For G7 Grayscale submissions, either the P2P51 target or a custom target containing columns 4 and 5 of the P2P, in a format readable by the testing facility (see “Are custom targets allowed?”).
  • For G7 Targeted submissions, either the P2P51 or a custom target containing columns 4 and 5 of the P2P and the six solid CMYRGB patches, in a format readable by the testing facility (see “Are custom targets allowed?”).
  • For G7 Colorspace submissions, either the P2P51 plus the IT8/7.4 target, or the new TC1617 target, or a customtarget containing all the unique patch values of the IT8.7/4 target and columns 4 and 5 of the P2P51 target, in a format readable by the testing facility (see “Are custom targets allowed?”).

Q: Are custom targets allowed?

A: Yes, but note that using the supplied Idealliance P2P51 and IT8/7.4 targets, or the TC1617 target is cheaper.

  • You may use custom versions of these targets under the following conditions;
  • The new target must fit on the automated equipment available at the testing facility.
  • The application must supply an i1Profiler-compatible reference file which enables the custom target to be measured on the equipment available at the testing facility.
  • The new target must measure at the same speed as a standard target.
  • Custom targets should be approved by the testing facility prior to submission. To check if a target can be used please submit request to Margaret Hyman at mahasp@rit.edu.
  • There is an additional $50 setup fee, per application, for each different custom target design submitted.

Note: If a target is submitted that has not been pre-approved and does not meet the above design requirements, any part of the application using that target will be deleted from the application without refunding the $50 fee.

Q: What is the TC1617?

A: The TC1617 is a new characterization target developed by Idealliance that contains all the CMYK patch values of the IT8.7/4 (with duplicates removed) plus all the CMY and K-only values of columns 4 and 5 of the P2P51, using the same number of patches as the IT8.7/4. Benefits of the TC1617 include:

  • No need to measure two separate targets for G7 Colorspace testing.
  • Reduced image area on G7 Master test prints (no separate P2P required).
  • Reduces the cost of G7 Master Colorspace applications.
  • Potential for improved neutral gray accuracy in ICC profiles.
  • Compatible with most, if not all, ICC profiling software packages.

Idealliance supplies TC1617 target images and i1Profiler workflow files compatible with the X-Rite i1iSis 1 and 2 (standard or XL size) and the i1iO 1 and 2. The P2P51 gray patches are arranged in contiguous columns to help minimize the effects of uneven inking across the printing area. The i1iSis TC1617 is supplied in two versions with suffix H or V, where the gray scales are on the short side (H version) or long side (V version). The i1iO has only one version with the gray scales arranged on the short side. One on each page of the chart.

Q: Are custom CRPCs allowed?

A: Yes. G7 Targeted or G7 Colorspace submissions may aim at any of the standard Idealliance G7 CRPCs, or a custom G7-based CRPC, so long as the custom CRPC reference data are uploaded with the submission in a standard CGATS text format, readable by RIT. There is an additional $50 fee per application for each custom CRPC submitted, in addition to any fee for custom targets. Note: custom CRPCs that do not meet G7 Grayscale requirements will automatically fail G7 Master submission.

Q: Are QR codes mandatory for every form?

A: Yes. As of July 15, 2016, the currently-valid QR code MUST appear on every test form, and test forms must be submitted UNCUT. All standard test forms on the Idealliance website will be updated to include a space for the QR code. If creating your own custom test form, just make sure to include the current QR code on it.

Q: Where should QR Code be printed?

A: Print QR Code on the same side of target.

Q: How do I figure out the tolerances I need to meet on the sheets I submit? How do I know if my sheet will pass?

A: All tolerances are described in the document “G7_ master_pass_fail_v33_2016” (or the most recent version) available at idealliance.org/g7submissionkit. You can use commercially-available software, your own spreadsheet, or manual calculations to determine if your printed sample meets the requirements.

Q: Where can I find more resources to become qualified as a G7 Master?

A: G7 submission related documents can be found hereG7 videos are available here, and discussion boards can be found here idealliance.org. Additional questions should be directed to Jordan Gorski jgorski@idealliance.org