INDUSTRY STANDARDS — FOR THE COMMON GOODSeptember 2006
The GRACoL Committee found the ISO standard’s “reliance on a small number of solid ink colors and TVI curves limits its value in ICC color managed workflows. The main problem is that ISO 12647-2 is ambiguous due to the use of multiple TVI curves, and the lack of a colorimetric definition for gray balance. Today’s users want a printing standard to define the ‘appearance’ of the final image more precisely than is guaranteed with ISO 12647-2.”
GRACoL 7/G7 eliminates the TVI problem entirely by replacing the ISO standard’s multiple TVI curves with the new concept of a single neutral print density curve. NPDC is described as a new concept based on the relationship between measured neutral density and original halftone percentages on a printed gray scale. “Because neutral density is an absolute value, while TVI is a relative function, NPDC ensures a better contrast and density match between multiple devices,” explains the how-to guide.
According to its developers, “The primary advantage of the G7 calibration method is that the visual appearance of neutral tones and near-neutral colors is more effectively controlled than by traditional TVI-based methods. The main disadvantage is that gray balance can be a challenge to maintain in offset lithography.”
Some members of the U.S. printing community have questioned the usefulness of promoting gray balance as the preferred control mechanism ahead of TVI. The strongest dissent, however, has come from the European community. Olaf Druemmer, chairman of the European Color Initiative, become the unofficial spokesperson for this group that argues in favor of continuing to use the ISO 12647 family of standards. Its members see no compelling reason to replace the standard and walk away from the decade’s worth of experience with it.
G7 was not developed to be in competition with ISO printing standards, but instead should be seen as a best practice for implementing ISO 12647-2, reports Dianne Kennedy, vice president, publishing technologies, at IDEAlliance. Kennedy says there’s growing evidence of the process taking hold globally, but she also acknowledges that some printers are reluctant to change to the new techniques.
The IDEAlliance G7 Expert Program has trained leading pressroom and color management professionals from companies across the United States, Canada, Latin America, Europe, Asia and Australia, she adds. Further, a test designed to compare traditional ISO 12647-2 printing methods with the new G7 method was organized this past July by the BPIF (British Printing Industries Federation) Technical Standards Committee.
“A color test form was designed and prepared to incorporate both the Fogra and GRACoL G7 control targets,” Kennedy notes. “According to BPIF, ‘When both sets of printed sheets were subject to close comparison, the color and appearance of the two tests results were remarkably close, which indicated…both (Fogra or the GRACoL G7 ) could achieve the ISO 12647-2 standard.’ ”
SWOP (Specifications Web Offset Publications)
In a related move, this past spring IDEAlliance announced an initiative to “modernize” SWOP in response to changing needs reported by users. Speaking for the group, Jim Mikol, senior vice president of technology at Leo Burnett USA and member of the SWOP Advisory Committee, observed, “Our industry has changed since SWOP first developed its specifications, yet SWOP has not (changed). We now demand tighter tolerances and greater assurance of a close visual match from proof to printed publication.”
At the time, IDEAlliance revealed it intended to apply the G7 methodology as the foundation for updating SWOP as well, and it suspended proofing system certifications pending completion of that work. The announcement asserted that, by using G7, “the outcome will be a new visual appearance-based SWOP specification designed to enable printers to quickly and accurately replicate visual appearance from proof to press.”
Kennedy says another key part of the modernization effort was adoption of a new No. 3 grade paper as an approved SWOP stock along with the existing No. 5 grade groundwood publication paper.
Some six months later, IDEA-lliance is now in the process of relaunching the SWOP proofing system certification program, reports its vice president. The two stock options (No. 3 and 5) have been included, as well as a new GRACoL option for proofing commercial printing. The official launch of the “new SWOP” was to take the form of an IPA Webinar on September 13.
According to Kennedy, proofing system certifications for SWOP and GRACoL will resume this month. “The hard-copy proofing certification will be ‘to the numbers’ and the monitor proofing certification will move ‘to the numbers’ by early 2007,” she says.
Job Definition Format
JDF remains a specification, and not a formal standard. Its ongoing development continues to be under the direction of CIP4 (The International Cooperation for the Integration of the Processes in Prepress, Press and Postpress).
Industry vendors largely have shifted from talking about JDF support, as such, to instead promoting the workflow integration and efficiency its use enables. The pendulum may swing back, though, as PIA/GATF ramps up the JDF Product Certification Program at its facility in Sewickley, PA.
Any products—equipment or software—submitted for testing that receive a passing grade will have the right to bear a “JDF Certified” logo. This logo can be used on packaging and in promotional materials to indicate that a product has been certified as meeting formally established guidelines for interoperability.
According to CIP4, JDF Certification shouldn’t be interpreted as “plug-and-play” connectivity. Any two JDF-enabled devices that are interfaced will still need to be set up appropriately in order to communicate seamlessly.
Serving as the foundation for this testing are the Interoperability Conformance Specification (ICS) documents developed by the various technical working groups of CIP4. Products are to be assessed based on their stated level of JDF support: read (manager), write (worker) or both.
Results will be judged on a straightforward pass/fail basis, says James E. Harvey, executive director of CIP4. Basic information from testing—including product model/version, “go/no-go” results and ICS used—will be published, Harvey adds. In cases when more detailed reports are generated, usually for a failing product, that information will not be released to the public, he says.
As for the specification itself, “work is underway on JDF 1.4, but it isn’t due out until next year,” Harvey reports. CIP4 has signed a cooperation agreement with IPA, The Association of Graphic Solutions Providers, under which the latter will take a lead role in further development of the specification in the area of content origination, he notes. “This will be a major area of expanded coverage for JDF 1.4.” PI
PRINTING IMPRESSIONS would like to thank William B. Birkett, print quality consultant with Doppelganger LLC, for providing background information for this part of the coverage.