Hi,
For disclosure I'm a Xerox analyst.
When I setup stocks for a machine, I follow these simple rules to ensure great results.
-1- ENSURE your drums are in good shape! For profiling at least 80% on each. in color quality the base of the pyramid is the quality of your hardware.
0- Create a Custom Paper Settings for everything (I'll explain why later).
1- On anything above 210gsm, run both the density uniformity adjustment and the image transfer adjustment. I only saw the density uniformity tool used once on a bad stock but I run it anyway once at setup, just in case. Unless your drums are almost dead and your belt is equally almost dead, and even then, maybe only on 350gsm, you shouldn't need the density uniformity tool. I saw it used once on a V80, and once on a 3100, on all my customers.
2- As I said, run the image transfer after the density uniformity adjustment to ensure that the stock has the best results on solids. If your humidity/temperature seriously goes out of whack later, run it again if you see a change. It'll help. When humidity goes close to zero, that image transfer tool will help.
3- Create your alignment for the stock 'Tray 6 12x18 Silk 300' and stick to a certain nomenclature of your choice to make them easy to read as your create more over time. Tray 6 and 7 are pretty much interchangeable for alignments so are 1-2-3. They stick, also, FAR longer than any previous machine and they take 2 minutes to makes. Simplest process in the industry.
4- Run at least 25 sheets before calibration, given your drums and everything else is in good shape. You can't calibrate a cold machine it won't give you optimal results. (this may actually be deprecated but its an old habit I'd have to run a fogra strip across first and 25th sheet to ensure this... I'll do that eventually but for now, its an old recommendation to run a few sheets first. Best time? Middle of a shift.
5- If you have iProfiler (ideal) or CPS (buggy, brownish grays) then only use the defaults 90gsm plain /120gsm coated to segregate your stocks based on coating. The profile will take care of everything else. There is no perceivable difference these days if you create a custom calibration set or not for each stock. I sampled delta e and saw under 1 so no visible difference. Its insanity to do it the EFI way with a calibration sets per stock you end up calibrating all the time. I'd only do a custom calset if the white point or texture was vastly different.
6- At that point run your targets and profile your stocks. Then import them and assign them to the paper catalog in Fiery so you don't need to always specify which profile for each stock. Usually on a Versant a profile for uncoated and a couple for gloss will get you through GRACoL compliance for everything. You don't need to go nuts with a profile per stock. You don't need 4000 or 6000 patches either. The 1417 or so standard works just as well. This isn't a linear relationship between number of patches and quality. It tops off around 1500.
7- If you don't have a profiling software nor a spectrophotometer than try to use, over time, the same stocks when you calibrate and calibrate each of those five. If you are using plain paper, put about five sheets over your target when placing it on the glass.
8- The rare times you need a custom calibration sets are usually when your stock has a very different white point or a vastly different texture that's messing up the Fiery. If you do create one, call it 'Custom CalSet xyz' so that in the list you'll remember this ain't a profile. Its a calibration set.
Now a bit of background.
When you calibrate, you are essentially ensuring that at 0%, it ain't dripping. Just like a plumber. You're ensuring that at 0,10,20,30% etc each of those primary colorants outputs the optimal quantity of toner. How do you know what's optimal quantity you ask? Well, you are basing your results off a certain stock, i.e., the Xerox 24lbs plain for example. So they tweak those densities based on a certain stock. How well it looks on a given stock is taken into account. The paper is the N'th colour in any printing system... (TM by me! lol) That's why you have five calibration sets that covers most stocks. Those calibration sets are then tied to profiles. These ICC profiles, be them for a TV or a paper, are basically just a huge lookup table... for that LAB color, do this in CMYK, and so on. Its a two column spreadsheet which, from all those 1500 little squares of different color it scanned, tells the machine how to print colours accurately on this or that paper. Its like a pair of glasses for the machine and a certain paper. The profile also takes into account the white point of the paper. You see, depending if your paper has too much optical brighteners (ie its blueish) or its yellowish, that paper white point is essentially the N'th color in any printing system. It matters. So you can bet that any paper that has a white point close to the reference point of your default calibration set/profile combo will work well given a similar surface. If you never callibrate the 300gsm gloss and you are printing on that then you'll usually find you have a magenta cast btw. Having someone like me do the profile and colour training is usually worth it if you want stellar quality that is repeatable. People that calibrate sporadically on changing papers ensure that they have no consistency over time: the customer comes back a year later and they can't match the proof: they don't remember which particular paper they calibrated on back them and when etc. Try to ensure you stick to your house brands for calibration. Other thing: you don't need to calibrate all the time. Those days are gone. Look, when do you wax your car? Well, you look at your car, and decide right? Same with your printer. Get yourself a quality control document that exposes primary gradients, flesh tones, spot colors etc. and print that once the machine is pristine and calibrated/profiled. Keep it! Then print it again and compare that output before a colour critical job and you'll know if you need to calibrate. Remember, you need to calibrate the calibration sets that is the closest to the stock you'll print on. If you are doing glossy business cards then that's Gloss 300gsm. If you are doing a Cougar 350 then that's either Uncoated 90 (or a custom calset since that stock is hard). A custom ICC profile (not a custom calset) will give you far better definition in highlights and shadows, give you a crisper look and better more accurate color and details. If you reread this post a couple of time and stick to the recommendation you'll find having consistent color is easy.
9 - Use the Paper Catalog in Fiery to assign those profiles! I know I've said this but doing this will save you lots of problems and its far easier to set up job with the Custom Paper Settings integration into the Paper Catalog since you only need to have one dropdown: the paper catalog dropdown.
Okay, my fingers are numb feel free to ask me anything else cheers!