CMY Profiles

[Bill W]

Greetings,

I am interested in making a CMY profile. In either iProfiler or MeasureTool I see not way to limit my target / chart to only CMY. I have the measurement data that I used to make a CMYK profile. I noticed in iProfiler if I use that same measurement data and set the Maximum black slider to 0, my profile will contain no black.

Is this a valid way to make a CMY profile?

-Bill-

 

[Al Ferrari]

I am curious why you need a CMY profile to begin with? If you output an image containing only CMY data using a CMYK profile, you get valid output, no?

Al

 

[Stephen Marsh]

Hi Bill, in i1Profiler I would zero out as many black options as possible, although as you say setting the Max K value to zero may already do this, I prefer to turn off “intelligent black” and all other black settings to zero, just in case (perhaps just superstition). I also upped the total ink limit above 300% even though a CMY only profile can only have 300 total ink (the preview looked too weak, however there is no info palette to double check without first making the profile).

Anyway, it all seemed to work OK. I found that converting via perceptual intent resulted in solid CMY shadows, other intents did not result in solids (if this is required).

It is best to assume, softproof or assign a regular CMYK profile for the same print condition so that one is not mislead by the dense shadow preview when using the CMY profile.

Is this something you require for flexo packaging?


Stephen Marsh

 

[Bill W]

Greetings,

Certain digital presses have front end software that offers the option of converting PMS colors to CMY only. For many PMS colors this conversion is a good match, for others it is not. While printing with only 3 colors speeds up the press it also, when using the software's workflow, increases the click charges and forces one to use a generic curve set.

I was interesting in making a workflow that used our own CMY profile and then comparing the results of PMS conversion to the "packaged" software workflow conversion.

I am in the process of building and printing our own PMS conversion books for our digital press using different 3 C/P, 4 C/P, and up to 7 C/P conversion processes. These books will be used by our sales staff, csr's and production staff when deciding on how to run / price a job.

Thank you Stephen for taking the time to make and check a CMY profile. In regards to TAC, I tried both a 300 and a 400 setting when making the profile and PMS black converts to the same values, 96, 96, 100 regardless of TAC setting. That said, there will be labels that include CMYK images, so I will need to check TAC settings against some of our darker images and QC the results.

-Bill-

 

[Stephen Marsh]

Hi Bill, the preview image in i1Profiler looked very weak (overall) when I set the TAC to 300% with CMY only settings. I upped it to 400 and the preview image looked richer (go figure, as it can only achieve 300%). I did not take the time to compare a 300% and 400% profile to each other in their actual conversions, so this could just be a display thing with i1Profiler. Depending on your profile generation settings, you may be able to get a 100c100m100y shadow using perceptual rendering intent, when other intents max out slightly under 300% (for what this matters).

When GCR is done correctly and even more so for a digital device, the general colour appearance should be identical even if different GCR levels are used.

P.S. How much variation does your print have, in the same run, day to day , calibration to calibration etc? If the swatch books are not consistent with production... How are you making the charts, or which ones are you using?

Stephen Marsh

 

[Bill W]

Greetings Stephen,

First, we do the full color calibration once a month using the manufacturer's recommended procedure.

Second, we do a calibration each time we change a stock.

Third, we only print the books after the full calibration and "wearoutable / consumable" components are replaced in the press.

Fourth, we match new work against the PMS conversion printed book to make sure there is a match, and, save a label of the run on the color standard card.

Fifth, we match reruns agains the color standard card.

I would like to say all matches are made using a spectro, but they are mostly eye matches.

-Bill-

 

[neess]

Hi.
Does this mean you have success creating your own EPM profile?
I was looking to do exactly the same, but i only have ProfileMaker and dont really have the knowledge how to make a ICC properly.
Are you able to link your profile to a color strategy? are you measuring you a PMS book also?
Is it possible to get a copy of such a profile?
//Steffen

 

[Bill W]

You can check this by sending a file through your no K color strategy with graphics that include CMYK and PMS colors and then check the results in viewer.

You will need to make your own profile to insure it is a true snapshot of your press.