Interesting review of the new Red River paper but I confess to being confused. Mark notes that the difference in L* black point from the profile data but when one looks at data from an actual reading on the paper they appear to be identical at L* = 20. I'm trying to understand why the difference in profile values for the black point lead to the tonal separation that one sees in subequent data given that regardless of the profile, the printer can only print max black of one value. Maybe this was discussed during the last iteration of posts about M3 data, I can't remember.
Hi Alan, thanks for bringing this up. I do strive for maximum clarity, and I acknowledge that this subject matter can be confusing because of the number of variables at play, so if you are confused it could also mean that more or modified explanation is needed, so I'll take a stab at sorting it out. The disconnect in Black Point readings between what the M3 profile says when viewed in ColorThink Pro (L*1) and what comes out on paper when reading the Black patch with an i1Pro2 (L*20) happens on account of the disconnect that occurs when you create the profile using M3 measurement condition with a polarizer, but then read the results on paper from using that profile with an instrument that can only read M0/M1/M2 (all non-polarized). I don't know the physics or math of why that happens, but it does.
So, leaving the world of the profile and ColorThink Pro, and entering the world of the print and an i1Pro2 spectrophotometer, whether the print is made with their M3 profile or my M0 profile, when you measure the blackest Black patch that was laid down on paper, and you are making this measurement on both prints with an M0/M1/M2 instrument (e.g. XRite i1Pro2), you do indeed find that the value returned is L*=20. And when I look at the quality of the black with my own two eyes (forgetting all the instruments and measurements) in both target prints, it does look more like an L*20 Black than an L*1 Black. So, let us take as understood that whether using one profile or the other, the maximum black for this paper measures and looks pretty much the same when the same instrument is used for the measurements on both target prints.
The question of how the deep end of the tonal range gets reproduced from that point upward is another matter, and on this one, the measurements (using M0 measurement condition) and the prints of a deep shade target image (the Romans 16 low key B&W), are coherent and both indicate that the M3 profile used with Relative Colorimetric Rendering Intent does indeed provide enhanced tonal separation (higher contrast range) from L*20 to L*35 compared with the M0 profile. But you can tweak the M0 result to just about emulate (finicky adjustments) what the M3 does without tweaking. So the M3 does good things for Black shading appearance even though at the bottom end of the tonal range there is only so much blackness that a matte paper can reflect regardless of the profiling method.
Does this help?
