GRACoL Defines Commercial Printing Characterization Data
Press release from the issuing company
ALEXANDRIA, VA (August 8, 2002) - GRACoL(r) (General Requirements for Application in Commercial Offset Lithography), a publication initiative of IDEAlliance, announced today that an agreement with CGATS, (Committee on Graphic Arts Technical Standards), has been reached to finalize color aims for commercial offset printing. These aims will take the form of color characterization data relating all input combinations of yellow, magenta, cyan, and black dot percentages to output CIELab colors that a "standard commercial press" should produce for each of these sets of input values. This follows the successful format developed by SWOP (Specifications for Web Offset Publications) and CGATS for printing, certifying and measuring publication press sheets on grade 5 papers as documented in CGATS Technical Report TR 001.
"Up till now, GRACoL has limited its effort to publishing a very successful process control publication for commercial printers and their customers," said David Steinhardt, CEO of IDEAlliance. "This included recommendations for density, line screen ruling, tone value increase /dot gain, total area coverage and print contrast for printing on various types of paper. Over the last six years, however, the public has increasingly demanded that these become fully defined printing conditions like CGATS TR 001 for SWOP." GRACoL has begun this process by printing and certifying samples printed on grade 1 paper by a high end commercial sheet fed press at LAgraphico in Burbank, CA, and submitting them to CGATS for measurement. In a parallel development the GRACoL committee has also been involved with printing and certifying samples printed on grade 3 paper by a commercial web offset press at Quad/Graphics in Wisconsin and submitting them to CGATS.
The standards community has generally agreed that eventually there will be a family of 5-8 standard characterization data sets representing all major differentiable printing applications from high end commercial printing to newsprint, based on paper types," said David McDowell of CGATS. These data sets will be documented in the form of CGATS Technical Reports. "These data sets will be broadly representative, and intermediate printing types, such as commercial printing on grade 2 paper which has the same GRACoL aim points as grade 1, may be considered to be variants of the basic standards and more easily handled by using color management to transform data from one of the standard data sets."
Results from both printings have been measured and analyzed by CGATS and reviewed by the GRACoL Committee. "GRACoL has agreed that they represent their intended printing conditions," said David Hultin, IDEAlliance Project Director of GRACoL. "But, as has been learned from TR 001, we will not base an industry standard on a solitary printing." Instead GRACoL and CGATS plan to conduct reproducibility tests, collect samples of press bars printed to GRACoL aim points, and verify that the printing inks meet the appropriate parts of ISO 2846.
The goal is to have drafts for CGATS technical reports TR 003 and TR 004 by the next CGATS meeting in October. "If successful, we would expect to be able to submit the Technical Reports for ANSI public review in early 2003," said Mary Abbott of CGATS. "The outline of the reports include: Scope and applicability, References, Terms and Definitions, Printing condition aims, Summary of actual test conditions, Evaluation of test conditions achieved vs. aims, Report of endorsing organization, CGATS qualifications, Concerns, Endorsements and Characterization data (CIELAB vs. CMYK), plus technical Annexes."
Printers and industry vendors, who wish to learn more about the transforms can contact David Hultin at IDEAlliance for more information. At the present time, the work is in the development stage, and it is assumed that there will be slight modifications to the data before it is formalized by CGATS.
"Everyone involved in the process believes that this is the most important development for the future of Commercial Offset Printing," said Larry Warter of Fuji Photo Film, o-chair of the GRACoL Press Run Committee. "A unified transmissible color target for printing and proofing coupled to the recent advances in color management from ICC will give our industry the quality, consistency and speed that will be required to keep printing viable in the future."
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