News flash  |  22.12.2006
 

Two new sets of characterization data:

 

FOGRA39 substitutes FOGRA27

 

Dipl.-Ing. Andreas Kraushaar

 

Figure:
Comparison of the new ISO 12647-2:2004 / Amd 1 [red] values and FOGRA39 [green] in the CIE a*b* plane [projection] – click to enlarge.

 

 

ISO TC 130 has made tremendous progress in the past years to further establish well designed and widely recognized standards in the graphic art industry. The collaboration between Fogra, bvdm, ECI and Ugra based on theses standards showed a great progress in establishing characterization data namely from FOGRA27 up to FOGRA32. The ICC profiles built on top of theses data sets such as ISOcoated.icc or ISOWebcoated.icc did a tremendous job in separating data as well as in hardcopy and soft proofing. Briefly characterization data comprise the relationship between CMYK tone value patches and the corresponding CIELAB colour values for a given printing condition. The extension “L” to be found in the file name, such as FOGRA39L, stands for the extended data set comprising 1617 patches defined in ISO 12642-2, while no “L” reflects the valid subset of ISO 12642-2 comprising 1485 patches. The latter one is widely know as “ECI2002 test chart” used e.g. in the Altona Test Suite.

Based on extensive praxis tests the process standard ISO 12647-2, reflecting the fundament of the Process Standard offset printing [PSO], has been slightly modified with respect to the solid coloration. These changes are covered in a separate document called ISO 12647-2:2006 DAM 1, which amend the

valid standard ISO 12647-2. Due to this changes a new characterization data set has been created namely FOGRA39. It totally reflects the current primaries defined in ISO 12647-2 DAM 1. Problems and difficulties due to different aim values between the proof and the one stipulated in ISO 12647-2 belong to the past. However it was necessary to slightly adjust the secondaries green and blue toward more practical aim values. Figure 1 shows these changes graphically in the CIE a*b* plane [projection]. The tone value increase curves have kept unaltered ISO curves A [CMY] and “B” [black]. Therefore changes in the transition from FOGRA27 and FOGRA39 especially in the process calibration step will be minor.

Keeping good practise the new characterization data are available free of charge at "Products area" of the Fogra website and the corresponding ICC profile, named ISOcoated_v2_eci.icc, at www.eci.org. Besides FOGRA39 another data set will be published representing web offset printing on sc-paper – FOGRA40 [ICC profile: ICC-Profil ISOsc_eci.icc].

Media wedge aim values for both FOGRA39 and FOGRA40 will be incorporated into the new version of the media wedge evaluation - „MKCheck10.xls“, available from spring 2007.

Andreas Kraushaar
www.fogra.org
 

Tel. +49 89. 431 82 - 335
kraushaar@fogra.org

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