How much of a magenta cast? Is this something we'd need to squint to detect? Or is this so obvious that the colors aren't even close? There can be lots of reasons for this, but we would need more details to narrow in on the problem.
You've described a general problem (color not accurate).
I'll offer some general information below which may not be helpful (but at least you'll have an idea of what might be happening).
If you can please share some specifics... which OS & version are you using?
What software applications are you using to print?
Are you using Canon Print Studio Pro package?
Specifically which paper are you using (brand & model)?
You mentioned this is a Canon PRO-100
You mentioned this is running all Genuine Canon OEM inks (no third party ink)
You mentioned nothing is clogged (I assume you did a nozzle check and that came out good).
What quality level are you using for the printer?
When you print, did you select BOTH the correct ICC profile *AND* the correct paper type?
A "color gamut" is the range of all possible colors that a device is capable of producing. Your monitor has a gamut. Your printer has a different gamut. This can be tricky because monitors emit light ... but paper merely reflects light (more specifically the inks "absorb" the colors that you are not supposed to see, and reflect the colors you are supposed to seee. But this means color is accuracy is actually somewhat dependent on the quality of light in the room when you view the print.)
This problem has been around for ages and the "fix" is to apply something called an ICC profile.
The "additive" primary colors are red, green, and blue. But the "subtractive" primary colors (what a printer uses) are cyan, magenta, and yellow. e.g. to make "red" you blend magenta and yellow. Printers typically also add black. They also frequently will use more than one of each type of color (a printer might use "magenta" and "light magenta"). Adding extra color tone cartridges improves the color gamut for the printer.
To complicate things even further... different papers will absorb the ink differently. Some papers have "brighteners" in them which will also cause colors to look different even though it's the same printer and the same ink.
The ICC profile is created using special software and tools (which you don't necessarily need to own).
The idea is that the software will tell the printer to produce certain colors and, in a perfect world, it would. But then a measurement tool is used to test if the color is accurate using a colorometer (sort of in the same way that you can take a color swatch to the paint deparment and the home improvement store and they can mix up a bucket of your color). After the measurement, it determines if each color is accurate and/or if the color hue requires a stronger or weaker saturation of some ink in order to produce a more accurate version of that color. These results are used to build the ICC profile.
But imagine that the home imrrovement store doesn't just ask you what color you want... they ask you if you plan to put it on wood, drywall, plaster, brick, or plastic, because the color will come out different on each material. Painting a wall involves a heavy amount of pigment based ink. Your printer is apply a very light coating of "dye" based ink that absorbs into the paper. This is why the specific paper makes a big difference. So the ICC profile isn't just for the "printer". It's for the "printer / paper" combination (and actually it's for the "printer + ink + paper + quality level" combination). They generally wont ask you about ink because they presume you are using OEM ink with no third party tanks.
The ICC profile tells the printer what colors need extra saturations of ink ... and which colors need less saturation of ink... for that printer/ink/paper combination (and if any of those three things changes, you need a different profile.)
The reason you might not need to own calibration software and hardware is because most paper vendors already own these tools and they've pre-built the profiles for you. E.g. for your "Canon PRO-100" using Canon OEM ink, you can not only get an ICC profile using Canon paper, you can download ICC profiles for most third party papers as well. But this means you will need to have downloaded and installed the ICC profiles for all the different paper types you use.
One thing that can go wrong is that you've got photo printing software which can apply the ICC profile. BUT... it doesn't actually go straight to the printer. It goes to the operating system's printer queue. That print-queue ALSO has the opportunity to apply the ICC profile. You must make sure that the correct ICC profile is applied only ONCE. Applying it once fixes problems... applying it twice over-corrects and you are back to a inaccurate result.
There is also something called a "rendering intent". Depending on the software, you *might* run into words like "perceptual" and "relative" color "intent". Remember I mentioned that the printer cannot produce every color that your monitor can produce. The question is... what do you want the printer to do when it is expected to print a color it can't accurately produce (and it knows it is an out-of-gamut color)? The "intent" is the setting that lets you decide how you want the printer to handle this.
You have a choice... print all colors that CAN be accurately produced in their accurate color and nudge the colors that CANNOT be accurately produced to the nearest color that can be printed. This choice is called "relative" intent.
The problem with "relative" is that you might have two adjacent and similar colors that need to be different but are very close to each other... one that the printer can produce, and the other cannot be produced. If you use "relative" those colors might print the same and you lose the ability to tell the difference. To solve this, the print could nudge the color it CANNOT produce to the nearest color it CAN produce. But having identified that new color... find any other colors that would match ... and nudge them as well so that, while not technically accurate... at least your eye can see the difference. This is called "perceptual" intent.
Most of the time, the print output you will like better will be the "perceptual" version.
So...
1) Make sure you install and select the correct ICC profile for your specific printer / ink / paper combination. But what I didn't mention is that printers can also have "quality" settings (low, medium, high, etc.) and this can also change the ICC profile. My printer has some profiles that indicate quality "1/2" (quality level 1 or 2), and a different profile for quality "3" (the best quality).
2) Make sure you select that correct ICC profile ONLY ONCE (either in the software you use ... or in the print queue. But not both places or you over-correct and get bad results.)
3) If the software asks you which rendering intent to use... know the difference between the two most common choices (perceptual vs. relative). You probably want "perceptual". "relative" is mostly used for testing printer accuracy or for things such as product photography where absolute color accuracy is more important.
What if that doesn't work?
There are online services that will produce a custom ICC profile just for you. Typically they have you download their own test print and you print a page following their instructions. You mail the physical prints back to them. They scan your prints and build a custom profile ... which you download. They prices vary. If you just have one or two favorites papers you always use, this might be the more cost effective way to get a custom profile.
If you have lots of different papers... the cost of getting a custom profile for everything via an online service will add up and it'll be cheaper to buy your own calibration device.
I've used the X-Rite ColorMunki Photo (now called X-Rite i1 Studio). It's just shy of $500. These days I have an X-Rite i1 Photo Pro 2 (more than $1000). Not cheap. Anyway these devices will let you build your own custom printer profiles -- you do't rely on the ICC profiles from the vendors and you can even build profiles that include non-OEM inks.
It is usually not necessary to buy your own color calibration tools if you are printing for yourself, your friends, etc. I find my own printer (a PRO-10) actually does "pretty good" if I disable all profiles and let the printer auto-manage it's own color (and in some cases turning on a profile gives worse results). If you were operating a business, then you'd probably be more obligated to provide accurate colors and that's where these tools pay off.
Tim Campbell
5D III, 5D IV, 60Da
