Consistent Saturation Different Sources

[TerryWyse]

This thread has prompted some questions in my little brain.

1) If a customer sends an image in CMYK mode to my print shop, my understanding is that the halftone values in the image do not change as it passes through the workflow.

2) The halftone values in the CMYK image may change though if there are some kind of curves being applied when the plate is imaged.

3) How the customer see's the CMYK image on their screen vs how I see the same image on my screen will be affected by what profile has been embedded (and whether I honor it or strip it out) in the image - however the halftone values in the image do not change. Just how they are displayed.

4) Irrespective of the embedded profile, the display of the CMYK image will also depend on the calibration and profiles associated with my monitor vs that of my customer - but again, the values in the image remains unchanged.

Put another way - if my image is CMYK and only consists of a 50% cyan tone then a 50% tone value will be sent to the plate (and may or may not be altered by a transfer curve at the plate imaging stage). However, the hue of that 50% cyan in my CMYK image will change according to what profile has been embedded in it and the calibration state of my display device.

Is all the above correct? Or am I confused? Or...?

Thank you, J

#1: Depends on your workflow. Most folks would design their workflow such that CMYK values are not changed as it passes through the RIPing process (when you say "workflow", I interpret that specifically to mean your "RIP" workflow system such as Harlequin, Prinergy, Rampage, Nexus, etc., not your overall workflow). But it's becoming more common to introduce file/color conversions into the workflow itself. Much of this (and the questions that follow) become more about whether you see your job as delivering to plate/press the halftone values in the original file/image vs. delivering the *color* the customer expects...these can be two different things. I would contend that it's the prepress/printer's job to deliver on customer expectations and not adhering to some rigid notion that their job is to simply image halftone values to a plate.

#2. Certainly. I find many printers that consider themselves "anti-color management" and believe their job is to deliver exactly what the customer supplied to them in terms of halftone values....but these same printers don't have any qualms about altering these dot values via a dot gain compensation curve during plating! Like it or not, this is a form of color management that is altering the customer's data. If you're willing to take that step, why not do it correctly and start implementing a sound color management workflow?

#3: Of course. But, assuming you both are working on calibrated/profiled displays, you should essentially see the same thing as the customer, assuming you've honored their profile. As far as "stripping out" the embedded profile, I would say this is a questionable practice. At the very least, this is your clue as to both what the customer was seeing on their display (and possibly proofed) and the printing condition they separated for. You could elect to take this information and use it to perform a proper conversion to your specific printing conditions or simply ignore the profile and pass the values through your workflow as-is....but you should take this embedded profile as a way of the customer telling you what this image is supposed to look like. You ignore this at your own peril in my opinion.

#4: Yes, of course, but I would contend that if both you and your customer have taken the step(s) of calibrating/profiling your displays, there's a reasonable chance that what you're seeing on your display is not substantially different than what they were seeing. Sure, different profiling packages and measurement instruments will result in visual differences, but I don't believe these differences are enough to throw out the baby with the bath water. I'll take my chances with a calibrated/profile display than not!

As far as your "put another way" example, all things being equal, yes, you're correct....but you also need to recognize that there's several ways you set yourself up for an unintended conversion of these values if you do not have your applications and your workflow set up correctly....and the answer isn't to simply "disable color management". There's smarter strategies than that.

Regards,
Terry

[J]

Thanks Terry!

I find that sometimes people use vague or incorrect terms when posting questions and answers, which in turn makes me a bit confused about what I think are the basics of the process and what they are describing they're doing.
Thanks for the clear answer and reassurance.

J