Stange color behavior

[Seeking Knowledge]

Hello all,

I was hoping for some fresh eyes on my problem. Recently I had some work done to our wide format UV printer where a lot of heads were changed. I re-profiled the machine using the built-in RIP tools and an X-rite IO. Our colors are coming out way too saturated in the mid tones and the quarter tones on our test prints. This is compared to a test print made last year and a proof that was around the same time. The grey balance bar at the 75,64,64 reads really heavy too. They measure at C=.95, M=.95 and Y=.97. I am using the same tools as the previous build with all the sam settings applied.

Why would the profile be coming out so heavy compared to a year ago, could my I1 be out of whack? Is there a away to edit the profile to make it less heavy and bring the grey balance into line?

Thanks in advance for any help.

SK

 

[Stephen Marsh]

Before profiling, did you setup a new linearisation and calibration?


Stephen Marsh

 

[dabob]

I have heard that measuring devices need to be calibrate at least annually . . . not that we do it that way - but if all else fails . . . check the tools

 

[Seeking Knowledge]

Hello Stephen,

Yes I did the linearization, not sure what you mean by calibration.

SK

 

[Seeking Knowledge]

Hello dabob,

I contacted X-rite today and they told me about annual calibration as well. That is something I am looking into now. I am also trying to see if I can borrow another Spectro to see what my results would be.

SK

 

[Stephen Marsh]

Hello Stephen,

Yes I did the linearization, not sure what you mean by calibration.

SK

It depends on the RIP software, my experience is with proofing, WF production may be different…

With Kodak Proofing Software, one creates a “Media Configuration” file. This file contains total ink limit, single ink limit, grey balance, characterisation and calibration info. This basically describes the state of the printer’s native gamut on a particular paper at a particular resolution etc. A profile is built on top of this stable and known configuration. At regular intervals, the Media Configuration is (re)calibrated. A chart is output and measured, comparing the current output to the output when the Media Configuration and original ICC profile were created. If the current output is out of tolerance, then an algorithm adjusts the colour output and a new chart is printed and measured. This is repeated until the calibration is within tolerance or no further improvement can be obtained. This routine means that output from week to week, month to month, year to year can be consistent using a single ICC profile.

The process is similar for CGS ORIS Color Tuner, where the process is known as creating and calibrating a “Reference Printer Profile” (which also includes a linearisation). Again, charts are output and measurements are made and adjustments to output are performed in an iterative process until there is a minimum of variation between the original output and the current output.


Stephen Marsh

 

[Seeking Knowledge]

Hi Stephen,

The RIP we use is not like that, although they are out there, I know the Fiery Rip is like that and it is a Wide Format RIP. Ours one only does the Light/Dark ink transitions, Linearization (the single channel ink limit is handled internally), Total ink limit and then Profiling. It does not have an iterative process just print a test chart, read it and move on.

Thanks for you help.

SK

 

[rich apollo]

Just out of curiosity, what RIP are you running?

Is the calibration tile clean on your i1iO?

Usually something will have changed in the workflow - a change in the input profile, honoring embedded profiles, the addition of a simulation profile, honoring of output intents, et cetera.

 

[Seeking Knowledge]

Hello Rich,

We are using Caldera. The tile looks clean, I have checked every think I can think of to make sure nothing has changed and I do not see anything unusual. This might be an instance of not being able to see the forrest through the trees.

Thank you.

 

[rich apollo]

The relinearization should work, but... If all else fails, start from scratch. The heads may have been compromised a year ago when you did the initial set up. If you've got an iO, it won't take you very long.

 

[Seeking Knowledge]

Hello Rich, thanks for the advice.

We tried a re-linearazation and we got an error something along a the lines of the Chroma of the ink has changed, best to re-profile, which we did. That is when we noticed how saturated our prints were coming out. Our daily Spectro is a i1 I/O, we have tried an old DTP-20 pulse (it is very old we stopped using it years ago), it has yielded different results but nothing conclusive. They both measure the white point of the paper so differently the i1 says -3ish in the B channel and the Pulse says -1ish in the B. We have X-rite densitometer that confirms the white point as -3ish.

One thing I should mention is that if I use the old profile, created a year ago, the color looks pretty good. You can tell that there is a small color shift by reading the grey balance bars, they are skewed a little in the magenta direction. I just cannot figure out why we are now so saturated with the new profile. It is driving me bonkers, the deeper I get the more confused I am.

SK

 

[rich apollo]

I would start from ground zero and rebuild the media.

Is that an i1 or an i1Pro2? You still have a Pulse...working? Reminds me of something Mr. Miyogi said in The Karate Kid, "Man with a watch always know what time it is. Man with two watches is never sure."

If that's an older i1, is it UV-cut?

 

[Correct Color]

Well, here are the questions I'd ask:

What kind of printer is it?

Did you re-profile from scratch, or did you build on the old profile?

Do you feel you're pretty proficient with the profiling process in Caldera?

Since you did the work, have you tried printing with the old profile? If so, how'd it print?

Are you using an i1 Pro2, or an older model i1?


I'd just hazard some guesses though. First is that while it might not hurt to send your i1 back to re-calibrate it, I'd wager it's not off enough to create the issue you've described. However, not being a fan of the IO table at all, if it was me in your place, and I was confident in using Easy Media and sure I'd followed all the steps correctly, first thing I'd try -- particularly if it's an older i1 -- is taking the device out of the arm and re-making the profile by hand.

Also note that the process Stephen described is basically what Easy Media does in Caldera. You create a machine state -- single channel ink limits; linearization; multi-channel ink limits -- and then characterize the machine in the state -- the ICC profile. The only difference is that unless you add on some G7 silliness, there's no grey balance routine. And the reason is that it doesn't accomplish anything in large format printing, since it's always the ICC profile that defines exactly how the machine prints.

Offhand, I hate to say it, but it sounds to me like you're just making an error somewhere in your process. But given what you've described, it'd be hard to say just where.


Mike Adams
Correct Color