As most users of the iPFx100 and later printer models know, knowing how to utilize the in-built calibration function of the printer is vital to the optimal use of these machines. The way it works is has changed slightly in the iPFx400 series of printers, as Geraldo Garcia has pointed out in this thread. My own independent investigations led me to a similar discovery, and after reading this thread and exploring further, I would like to share my findings.
Prior to the iPF x400 printers, there can only be one active universal calibration, using one of the compatible media types. Recalibrating using the same paper, or a different media setting or a different paper will overwrite the previous calibration and the new calibration will be applied to all the installed media types.
For the iPF x400 printers, it is possible to have media specific calibration. Essentially, there are three general scenarios, and a special forth one which I will get to later:
1. First calibration: Performed on one of the "Common Calibration" media types, it is applied to all the media types installed in the printer, including the "Unique Calibration" media types.
2. Subsequent calibration on a different "Common Calibration" media type. It is applied to all the media types including the "Unique Calibration" media types, but not to any with calibration already performed on them.
3. Calibration on "Unique Calibration" media types. This is media specific and is not applied to any other media types. Subsequent calibration on the "Common Calibration" media types will not affect it.
The "Common Calibration" and "Unique Calibration" media types are listed in page 752-753 of the iPF Users Guide:
If one checks the Calibration Log in the printer menu, it will only show the latest calibration performed. For media settings that have its own active calibration data stored, the log will update to reflect this only when paper is loaded and that media type selected for the paper. To make it easier to keep track of all active calibrations, one can use the ImagePROGRAF Color Calibration Management Console. It lists the calibration status of all media types and it is easy to see when there is more than one calibration active.
This is the forth scenario:
Since the iPF x300 printers, the Media Configuration Tool has allowed users to create custom media types. It is not possible to perform calibration on custom media that end users can create with the MCT. Page 747 of the Users Guide explains why:
When using paper other than genuine Canon paper and feed certified paper
To execute color calibration on paper other than genuine Canon paper and feed certified paper, a Custom Media Information File that contains a dedicated Calibration Target is required.
As long as you have a Custom Media Information File that contains a dedicated Calibration Target for paper other than genuine Canon paper and feed certified paper that was created on a printer (12-color model) with a Spectrophotometer Unit mounted, it can be registered in the printer by using the included MCT and you can execute color calibration even on paper other than genuine Canon paper and feed certified paper.
So there is indeed some "Calibration Target" data (not reference data) that unlocks/allows calibration on custom media installed on printers without the spectro!
At this point, it means only the iPF6450 with the spectro accessory talking to its MCT can build this file. Once you have created the .am1 file, you can import it to any x400 printer and make media specific calibrations with just the built-in calibration function, just like Geraldo Garcia did with one of Canson's custom media type.
This part puzzles me. After conversing with Scott Martin over email, my understanding of the built-in calibration routine is essentially linearizing the printer for that paper. It is hard to imagine that the target is built into each .am1 file instead of stored on the printer. A check of my custom made .am1 file without the data is 945kb, and Canson's with the "Calibration Target" data is the same size. It is unknown as yet why Canon chooses to lock out the ability to calibrate on custom media for the other iPF x400 printers, and what importance the spectro accessory has to play in creating the target data.
I want the ability to calibrate custom media types. I think it is useful for all of us who don't use a RIP. Media specific calibration is the closest to RIP linearization - I like the well behaved linear state of the printer before profiling. Native printer performance on matte media is not as linear when doing a general calibration on glossy media. I should say though, that the differences are usually minor and only the fussy demanding sort of people will want to do this, and the profiling step afterwards usually levels out most issues.
If you own a iPF6450+spectro but you want to calibrate your custom media types, hopefully you have a nearby friend or a dealer that does and lets you borrow theirs. Page 749 of the Users Guide has the procedure for setting up custom media with the Calibration Target:
You can also reduce the variations in printed color tones when using paper other than genuine Canon paper and feed certified paper by creating a Calibration Target by using a printer with a Spectrophotometer Unit (optional) mounted and the included Media Configuration Tool (MCT).
You can also execute color calibration even if you are using paper other than genuine Canon paper and feed certified paper by registering a Custom Media Information File that contains this Calibration Target using the included MCT on a printer (12-color model) that supports calibration link without a Spectrophotometer Unit mounted.
Furthermore, it is also possible to execute color calibration on paper other than genuine Canon paper and feed certified paper even on remote printers (12-color models) that support calibration link by sending the Custom Media Information File that contains the Calibration Target by e-mail.
This allows you to operate efficiently and at reduced cost because you can perform calibration operations on the paper you are using that unify color tones across workplaces.
The following procedure using MCT is needed in order to perform color calibration on paper other than genuine Canon paper and feed certified paper.
1. Register the media information using Add Custom Paper.
2. Add the Calibration Target information in Create Calibration Target to the created custom paper.
3. Save as a Custom Media Information File that contains the Calibration Target.
4. Add the Custom Media Information File to a printer (12-color model) that supports calibration link without a Spectrophotometer Unit mounted.
5. Execute color calibration using the printer or the CCMC color management utility.
If one has a number of media specific calibrations, take note that in the event you are performing routine re-calibration to account for printer drift/print head change, do note that you would have to re-calibrate for all those media types again. For most users, the general calibration will suffice and makes life a bit easier. That itself provides the greatest output quality difference, and makes it easier to perform one-time recalibration.