Quote:
Originally Posted by geotzo
Thank you Nicolas,
I did not know about 39L, so I ll try that. Another strange thing I notice is that unlike other proof certification software that I 've seen, the strips provided with GMG proof control, are made for specific printers (ie E4800), which I don't understand, since it should be purely the iso standards we try to verify. That I figured out from the fact that color strip files are named by the type of printer to be used, is that right?
|
Geotzo,
no the strips are not designed for specific printers (Except the HP-Z Series).
You mix this up with color standards in proof control
which are based on a specific wedge.
In ProofControl you have a few color standards wich are linked to a specific printer and media. For example the gravure standards (PSR) or SWOP, because these color standards reflecting a certified/accredited system. An example: In ProofControl you have the standards PSR_LWC_Ex800_GMG250 (Epson printer/ gmg paper) and PSR_LWC_IRIS (Kodak Iris).
When taking a look i.e. in 40%C / 100%m / 100%Y / 20%K you see...
PSR_LWC_Ex800_GMG250: L 31.85 a 41.00 b 27.31
PSR_LWC_IRIS: L29.69 a42.44 b 31.04
...so a dE of 4.54!?
BUT: These Lab values reflecting the
same visual impression even if they are different in terms of Lab measurement, since the spectro does not consider the metamerism of the inks and media - but the human eye does.
This is also one of the reasons why "humans" seeing color differences on proofs created by different systems according to the same color target, if the profiling have been done "just by numbers" without visual references.
