Hello all together,
I´m currently discussing with a paper manufacturer recommendations for
FOGRA char-data / ECI-profiles for his papers.
For woodfree uncoated papers, it seems clear, that FOGRA 47 /
PSO_uncoated_eci.icc should be used.
But digging a little bit deeper into paper categorization and printing
standards, the situation is not so clear.
If we look at the gamut, FOGRA47 /PSO_uncoated is smaller than e.g.
FOGRA40 / sc-paper.
If we are looking at the the traditional paper categorization for
heatset printing, the WFU (Wood free uncoated) papers are representing a
higher quality grade than SC papers (both are uncoated materials, but
SC-papers have a higher amount of wood fibers than wood free papers...)
So far as I learned about traditional paper categorization, the WFU
papers can may be super calandered or not. If not, this are the typical
uncoated papers, which are used e.g. in sheetfeed offset printing with
data preparation according FOGRA47 / PSO_uncoated.
If they are super calandered (WFU SC), they are more comparable with the
SC-paper category but with a much brighter paperwhite.
*****************
L*a*b* 100 K an 100C 100M 100Y for FOGRA 47 and FOGRA40
*****************
Source: MedienStandard Druck 2010 from bvdm
FOGRA 47 Black Backing
100 K = L*31 a*1 b*1
100C 100M 100Y = L*32 a*0 b*0
FOGRA 47 White Backing
100 K = L*31 a*1 b*1
100C 100M 100Y = L*33 a*0 b*0
FOGRA 40 Black Backing
100 K = L*22.2 a*0,9 b*2,1
100C 100M 100Y = L*26,2 a*-1,6 b*-3
FOGRA 40 White Backing
100 K = L*22.4 a*1,1 b*2,3
100C 100M 100Y = L*26,6 a*-1,5 b*-2,8
The comparison of this values, shows, that the densities / amount of
color for FOGRA 47 (uncoated) is much lower than for FOGRA40 (SC-paper).
Especially for WFU SC, this leads to following question:
- If ISO 12647-2 papertype 4 is used as standardization target and FOGRA
47 / PSO_uncoated for data preparation, we have a quite small gamut
compared to FOGRA 40 / SCpaper.
On the other hand FOGRA 40 / SCpaper could not used as target, because
the whitepoint of WFU SC is very different to FOGRA 40 / SCpaper. A
better candidate for gamut and paperwhite could be theoretically FOGRA41
/ PSO_MFC. But technically , this profile represents another paper category.
Another possibility would be, that the paper manufacturer adapts the
available standardization targets, publishes target values for white and
black backing and makes characterization-data and an ICC-profile public
available. For PDF/X workflows the characterization-data would be
registered at
http://www.color.org
I would be interested to hear what other people are thinking about this
issue
Best regards
Jan-Peter
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