GMG proof control

[geotzo]

I think some of you are using gmg proof control. I would like to ask you what kind of strip you use to measure. I try to simulate ISO coated 27L standard, so I use that profile when printing via gmg, plus the ISO 27L strip provided from gmg proof control module and then I measure it. What I get as a result on the label is a De Average around 1.8-2.5 and a De Max around 5-6. Am I supposed to alter some settings in order to match ISO coated standards and get a lower De or is it straight forward as i use it and the numbers above are fine?

[Nicolas]

Basically, it depends on the specific color patches if your proofs are OK or not. The tolerances inside of GMG ProofControl have been taken over from the FOGRA rules for ISO conformal proofs. If your proofs are inside this tolerances everything should be fine. I assume the wedge you are useing is the "mediawedge", which have to be used for proofing according to ISO 27L. The wedge is not from GMG, it is licensed from Fogra and comes with the software.
There is also a document from FOGRA related to "certified" proofing, because some tolerances have been changed in April 07 (It should be somewhere on the Fogra homepage). In addition you should consider also the "new" ISOcoated 39L (ISOcoated V2), which is the successor of ISOcoated 27L.

[Nicolas]

I found the link to the Fogra document
http://www.fogra.org/products-en/dow...News_02web.pdf

[mfitz]

We are considering buying a Konica- Minolta 6500 with Fiery or creo rip to
ose as a contract proofer. Does anyone have any knowledge of this device. Also can not find out if it is swope certifed.
Thanks,
Mfitz

[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?

[stargate]

SWOP certified systems are here...
SWOP | Certification: Certified Systems 2004-2005
Derek

[Nicolas]

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.

[geotzo]

Thank you Nicolas, I think I understand it better now

[geotzo]

Ok, here's the thing now: I changed the control strip in Proof Control from ISO 27L to ISO V2 39L iso 1247-7 (right?), but the readings on the mediawedge(Eye1) that I ve been printing, come out FAIL, obviously... So where do I get the newer wedge, so I can load it into dotproof and hopefully get a pass within tolerances.

[geotzo]

Ok, got it now. I have changed the profile to ISO 39L and all came out perfect. Got 1,2Max dE and 2Av dE... God I feel so stupid sometimes...