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To me, a scientific process implies repeatable, constant results and that was the error of my ways. I did not factor in that "repeatable" and "constant" was also fluid.
There is that in the calibration process, but its just the starting baseline, not the end goal of the exercise.
For example of you religiously set Custom WB off a gray card and can manage to record a full range of detail at capture you will have a "nominal" baseline result out of camera and will not need to mess with it must. The camera becomes the baseline for "correct" color.
Shooting a subject holding the gray card after setting WB you can open it on screen. If you measure the card with the eye dropper the RGB values will be equal, confirming the nominal camera baseline of neutral color. If your monitor is correctly calibrated the card should also look gray on screen. But due to how adaptive color vision is your brain thinking it is gray because you set Custom WB from it and seeing R=G=B with the eye dropper will adapt your perception even if your monitor is slightly off.
That happens all the time. Someone will do a calibration, assume its perfect, but mess it up somehow resulting in the screen having a bias. They open a perfect photo out of camera, judge it by eye, and screw it up. That's where the gray card in a test shot is invaluable. You can open it, measure it, click on it to make R=G=B and have an objectively neutral starting point for your color. If for example your calibration is off and you open a file with the gray card and it seems a bit too warm, measuring the RGB values and finding them neutral will give you a clue the monitor is off. Trust the numbers, not your eyes.
Often technically neutral color might not convey the mood you want in the photo. Often you want a warmer or cooler vibe in portraits, depending on the mood of the subject you wish to convey. So you need to move off the nominal baseline, but ideally in some way you can objectively measure and judge. That's where color targets like the Macbeth are helpful.
This screen shot is of the camera profile section of ACR. When a camera is added to ACR Abobe recreates the preset styles for the camera:
What styles do is shift the color balances selectively WITHOUT AFFECTING GRAY BALANCE. For example here's a MacBeth chart with different styles applied. Note how the colors change but the gray column doesn't.
The reason it is important to keep neutral grays neutral is because when looking at a photo were you want the face a bit warmer than the camera captured it from the neutral baseline the viewer of the photo will still expect the white sweater to be white, not yellow.
In my workflow I open the test shot like the one above with the card target and tweek the color in the styles tab where I can adjust color without affecting the overall gray balance with the presets and slider adjustments. Then I copy/paste that adjustment to the other files in the batch. The color chart in the test shot makes it easier to see how the adjustment is shifting the color hue and saturation from the neutral baseline. So in that sense color is a moving target and the goal isn't making it neutral, its making it look good by eye.
After making the adjustment to the test file with the target if I make a test print from it before starting any other editing I'm able to see how it will change when printed. I don't expect it to exactly match the monitor, I just want it to look "normal" and "real" in the lighting were it is viewed. Starting with a file out of camera which has Custom WB and a full range of tone pretty much assures the print will look OK because that's how the process is engineered to work. The only things to screw it up are: 1) operator error; 2) inaccurate profile for printer/paper, or; 3) mechanical problem.
All prints have two things in common: white paper and solid CYMK ink. It's what happens in the middle that affects the overall perception of the photo. That's can be controlled with the middle slider in Levels. If a file overall looks darker when printed than on screen the solution isn't to make the max. black lighter, its to make the midtones lighter. A simple way to do that I open the file in Levels and move the middle slider left....
This is baseline nominal file on screen, but it will print darker...
Knowing that I will make a Levels tweek before printing to open the midtones to compensate for the "dot gain"...
The net result is that the lighter screen file when printed is a closer match to the "nominal" screen file.
When I edit files for screen display and prints I wind up with four copies of the file: 1) the camera RAW; 2) a "Master Edit" copy; 3) copies reduced and sharpened for screen display; and 4) copies resized, adjusted and sharpened for each print size. That might seem like overkill, but its necessary to account for the differences in output methods if optimum results are desired.