Combining the "Best" Parts of Measurement Files

[Bill W]

Greetings,

Let me start that for those that do not know me I am a narrow web (10" max width) flexo printer and deal with wavy dot gain curves when viewed in MeasureTool.

Because of my narrow web I am not able to use any of the standard profile charts (ECI2002, etc) and have any room for images left on my press "sheet". Using MeasureTool I created a custom 992 patch target that appears to make a good profile, thank you Michael for your feedback on my target, and allows me to place parts of images on my press "sheet".

I am using CGS for my color rip and it would not accept my custom target's text file during its iteration process. The good folks at CGS looked at the text file and discovered it was missing 1 of the 16 ICC compliant required patches, CMY = 100%, K=0%. I fixed this problem by changing the CMY = 100%, K=50% patch to the proper 0% for K patch in both the text file and the Photoshop target file. By the way I am wondering why MeasureTool made a chart that was missing any of the required to be ICC compliant patches in the first place.

I went back to press and printed the correct target, but this run created curves that were more wavy that the first run. Since the only difference between the 1st and 2nd run in the target was the new CMY = 100, K = 0% block, I thought why don't I just paste the line for that block from the measurement file for run 2 into the measurement file for run 1. I did this and then made profiles from both measurement files and they appear to be for the most part the same, and now I have a profile (Lab measurement file) I can use in CGS.

I also checked the solid ink dE differences between the runs to make sure they would not skew anything, and they were:

C - 0.6 (CMC2:1), 1.1 (Delta E 94)
M - 0.7 (CMC2:1), 0.8 (Delta E 94)
Y - 1.7 (CMC2:1), 1.1 (Delta E 94)
K - 1.1 (CMC2:1), 1.0 (Delta E 94)

Additionally, TVI between the two press runs was within tolerance.

Is there any reasons that doing this would cause problems that my lack of experience will not allow me to foresee?

Thanks to all that respond.

-Bill-

 

[meddington]

Re: Combining the "Best" Parts of Measurement Files

>By the way I am wondering why MeasureTool made a chart that was missing any of the required to be ICC compliant patches in the first place.

What standard are they saying this requirement comes from? Its not in the ICC spec that I'm aware of.

>Is there any reasons that doing this would cause problems that my lack of experience will not allow me to foresee?

The 100% CMY, 0% K is really not a very critical patch in my opinion. Good to have to know what your device is capable of in that area sure, but real world separations will contain significant black generation here. I would say you'll likely be struggling with press consistency rather than differences cause by altering your measurement data in the way you described.

If your concerned about it, convert some images using profiles from the intial and altered measurement data, and compare the results.