Digital and Offset Printing: Seeking Workflow Oneness
The basics of G7 were developed by Don Hutcheson of HutchColor LLC, who subsequently granted the intellectual property rights to IDEAlliance. Refinement of the process control methodology and its publication as a specification were initially handled by the IDEAlliance GRACoL Working Group. This led to the misconception that G7 was akin to GRACoL, rather than being applicable to a range of processes beyond sheetfed offset printing.
The G7 specification formally defines process controls that determine the “visual appearance” of an image as perceived by the human eye rather than a mechanical device. It breaks from the long-standing practice of focusing on dot gain and instead uses gray balance (neutrality) as the basis for defining the metrics of “visual similarity” in a printed piece. Controlling tonality is the other key component of the specification, which is done by employing the concept of Neutral Print Density Curves set forth by the development team.
Printers must complete and maintain a G7 Master qualification that is specific to the facility, rather than the company, to legitimately claim the designation. This involves doing an audit of the plant’s output equipment and calibrating all of the proofing and printing systems to G7 gray balance and density curves. Although not required, use of ISO-standard inks and papers is recommended.
The calibration work must either be done by, or reviewed and approved by, a “G7 Expert” consultant who is currently qualified by the organization. A link to the G7 Expert database can be found at www.g7global.org.
IDEAlliance charges a $400 one-time application fee and a $690 G7/GRACoL Network two-year membership fee. It doesn’t set the fees charged by consultants, some of whom offer a turnkey package that includes those costs. There is also a $95 yearly re-qualification fee.
The broader applicability of G7 was demonstrated in the recent announcement that QuantumDigital had received G7 Master status. Based in Austin, TX, the company said it was one of the first all-digital printing operations to complete the qualification process.