The Canon rep was flat wrong - that would mean a re-cal with every different paper you're using, and certainly chasing your tail. The internal calibration is designed to return the printer to a standard state that has nothing to do with profiles - just consistency - and the HW Coated paper roll supplied with my iPF for this purpose has worked just fine. The idea is to use the SAME paper for your periodic re-calibration.
About the dark, flat prints, a too bright and contrasty monitor is the by far the most common cause for this.
Pete
I believe you may have misunderstood my remarks.
Yes, as I stated, you can use the paper provided with the printer to color calibrate, but (according to the Canon rep) there are better papers available which provide a higher range of ink density on the paper. (The iPF6400 sensor is basically a densitometer.) Those papers (there are 17 listed available in North America) are listed in the User Manual and the paper provided for head alignment with the iPF6400 is not one of them. I only received five sheets of this paper and it is not labeled. I thought I would use it for color calibration as well as head alignment, but knowing that I would always need to color calibrate to the same paper, I wanted to know what it was so I could buy more of it in the future. The rep was unable to tell me what kind of paper it was and suggested I use one of the recommended papers instead. If that paper was labeled so that I could feel confident that I would always be able to obtain it in the future for calibration, I would have called it good and used it for that purpose, as you do.
But back to your point...
Yes, if you had profiles from different manufacturers who used different papers to calibrate their printers, then to get the best performance from their profiles you would need to recalibrate before using each profile, with the paper the manufacturer used to create their profile. Trouble is they don't tell you what that paper is, so, in general, it's not possible to do it, even if you thought it was worth the trouble. If you are getting satisfactory performance from those profiles then I would just pick a paper for color calibration and always calibrate to that paper, so at least you will get consistent results.
If you are using your own custom profiles, there is no need to recalibrate for every paper you use, assuming you made all the profiles with your own printer calibrated to one paper. As you state, the calibration only returns the printer to a [repeatable] state that has nothing to do with profiles. The only reason to recalibrate would be if enough time/use has passed, or perhaps a head has been replaced, that the consistency of the printer may have drifted and you want to bring it back to the same state again.
Note that I substituted "repeatable" for "standard". I did so because the term "standard" can be somewhat misleading, as there is no standard state that color calibration brings a printer to. It is "standard" only in the sense that if two printers are color calibrated with the same paper, they should be in the same state.
Yes, you should always use the same paper to color calibrate, and
that is exactly my point. If you color calibrated your printer to paper X, then made a custom profile for a special paper that you want to use for fine art printing, would you then use that profile to soft proof a print after you had color calibrated you printer again, but this time with paper Y. I don't think so because, as you stated, you should always use the same paper when calibrating. But that is likely exactly what the original poster is doing.
It is most likely that Hahn did NOT use the identical paper to calibrate their printer that the poster used to calibrate his printer. If Hahn color calibrated their printer using paper X and the poster color calibrated his printer using paper Y, then they are not calibrated to the same state and he is using a profile that was created for a printer calibrated to a different state. For that reason, he should not expect that profile to perform as well as it otherwise would.
I am new to this and have only printed with two kinds of paper from two manufacturers so far - Canon and Moab/Legion. The Canon profile has allowed me to use soft-proofing to quickly get my prints to look very good on that particular Canon paper. The Moab profile is worse than useless. If I soft-proof with it I get a result that is worse than where I started. I'm in the process of getting a custom profile made for my Moab paper and hopefully that will allow me to soft-proof for that paper. If the custom profile works substantially better than the one provided by Moab, then I'm guessing that one reason could be that their iPF printer is color calibrated to a state that is substantially different from mine, due to their using a different paper for color calibration. At least I'll be eliminating that factor.