I went to a short printing seminar with the local Epson distributor. Most of the information seemed sensible and in line with what I have read here. Some of the statements seemed controversial. The guy was a hands-on guy with lots of real-world experience, something that I respect (although I occasionally doubt his theoretical analysis, much like a great chef might make the best pasta I have ever tasted but his quasi chemistry explanation may still be ridicolous).
1. Rendering intent
Relative colorimetric clips colours that are outside of the reproducible gamut. Perceptual intent shifts colours that are inside the reproducible gamut as well, in order to provide some detail in saturated areas. Ok. But perceptual intent also shifts white-point, so never ever use this for e.g. bride shots (the white dress will be discolored). Is this true? I would think that white point is (attempted) locked, and weakly saturated areas are minimally affected, only "significantly saturated" areas have their saturation reduced so as to have some structure in areas that would otherwise be clipped?
2. Always use black-point, no exceptions. I would think that when high-contrast (typically B&W) low-structure is the goal, BPC might be in the way? (my understanding is that BPC is a kind of soft-clipping of blacks conceptually similar to the soft-clipping of gamut done by preceptual rendering intent).
3. When printing to Epson, use dpi values of 360/n (360,180,...) to avoid moire. My understanding is that printing at 180 dpi would mean that the Epson driver/hw would still have to resample to whatever the internal representation (e.g. 720dpi), and that Lightroom might do this job slightly better. Based on advice by mr Schewe & friends, I am printing at 720dpi if my image is >360dpi, and 360 dpi else. He was into really large prints, so perhaps the (non-stated) thinking was that if you are printing a 10MP image on a really large print, there won't be much small detail anyways, and reducing dpi to some small fraction of 360 allows you to limit the memory consumption, while still operating the printer driver/hw in a way that allows it to scale reasonably well.
4. Avoid using the development sharpening controls of Lightroom, rather set for e.g. 180dpi in the print module and choose among the 3 sharpening settings available there, as you will then apply sharpening after image scaling and avoid blowing up scaling artifacts. My understanding is that Lightroom applies image processing in whatever order the creators deemed optimal, independently of how the sliders and modules are organized in the gui, and that it makes more sense to think about sharpening for input errors, creative stuff and output errors separately.
5. Moab slickrock metallic silver works great on the 3880 (I have this paper and liked it on my dye printer, but I haven't gotten around to trying it on the 3880).
6. sRGB/aRGB/pro-photo/macbook displays cover X% of the visible gamut. This implicitly tells us how "good" their color is. It is my understanding that using percentages in gamut coverage is misleading the reader, a large percentage of the gamut space does not contribute that much to our perception of "accurate color".
7. Don't believe in any of the "nerds" that you find on the internet. They don't know what they are talking about.