I guess that's where we disagree - I don't consider the results from stimulating the paper with a uv free source any less real than stimulating with uv included. Both results are valid if they reflect real viewing conditions, and if those viewing conditions can be practically selected. I practiced for several years only using a normal i1Pro, and often had problems profiling OBA papers. I've been much more successful using the i1Pro uv cut for those papers. And for those of use still doing hand scanning it is significantly more work to scan with both instruments in order to compare profile results.
You measured Epson Prem Luster M0 b*=-6.72 and M2 b*=2.5. I measured RR UltraPro Luster M0 b*=-8.0 and M2 b*=-.6. I believe both M2 results are just as true as the M0 results, and equally useful. I agree that without the M0 measurements we wouldn't know anything about the OBA content, but that doesn't make the M2 measurements incomplete, they are sufficient to create a profile for use where the viewing conditions match, i.e. no uv.
Richard Southworth
Added by edit - I was answering Andrew, didn't realize other posts had occurred. BTW both of my instruments are i1Pro 1s, second generation.
The safest way to get a print profiled for more display conditions is selecting an OBA free paper and measure it with an UV enabled spectrometer then create the printer profile.
The second safest way is selecting an OBA free paper and measure it with an UV cut spectrometer. After that come the worst combinations. Starting with an OBA loaded paper like the one you have is asking for issues at some point. 99% of RC inkjet papers have OBA content, very few so little that it is no issue. The shift of the paper white in time can be caused by UV light, light, gasses like oxygen, ozone, dark storage after exposure. Framed behind plain glass the fluorescence effect already is reduced, behind UV blocking glass it is absent. Yet that does not mean the OBAs are totally free of degrading there. Display conditions vary and UV light may be part of it or not, either caused by daylight entering or not so good converted by fluorescents in the CFLs. In short it suffers more of changing conditions than paper without OBA does.
Since the introduction of OBAs in papers after WWII consumers are more and more used to a bluer white point where UV fluorescence adds brightness to the normal whiteness of papers. Paper manufacturers introduced the Brightness property where the blue part of the spectral range is used to measure the "light reflection", they promoted that Brightness property. Most RC paper bases used to apply inkjet coatings on are already containing OBA, the coating may contain them too. For an RC inkjet paper manufacturer it is harder to create a neutral paper without OBA that gives similar Lab L light reflection that papers with OBA can achieve by this physics trick. So when consumers like to get that OBA look and it is easier to make, you get the paper you have.
The spectral plot of a Red River paper close to your paper is attached together with some alternatives with lower OBA content. Your's is most likely a Mitsubishi manufactured type. The PIctorico one too but with less OBA and Red River has a similar one. The purple plot is one of the RC exceptions with almost no OBA, Epson Proofing White Semi-Matte. Little OBA in the paper base, plenty of other "normal" whitening agents aboard to flatten the spectrum reflected and no OBA in the inkjet coating. You probably will not like its texture and it looks warm despite being neutral in the CIE definition. The dot lines show the OBA as measured at the back of the paper (black underneath) so more or less the paper bases with OBA content they started with.
UV-cut spectrometer raw readings are massaged one way or another when printer profiles are created with them. The white point is not the white point when OBAs are activated nor is it the white point of the paper base as if no OBA was added at all, the created white point is a virtual one representing a generic neutral paper. As shown the brightness created by fluorescence can differ a lot between OBA containing papers yet near neutral white points are usual for the printer profiles created that way. From the left to 575nm an OBA effect could exist but goes unnoticed by spectrometers with UV cut lamps + UV cut sensors, depending on how flat the remaining reflected spectrum is a profile can be made but what is actually raw measured for some must be way warmer than neutral, red end high and steadily descending towards the blue side. In that sense the Lab a figure is more revealing when white point numbers are taken from profiles made that way, green/yellow reflection of that paper being low
and measurable, you would expect a positive Lab a number there but it is slightly negative in your profile. Green plot lines representing your paper.
Although it starts from UV enabled measurements and aims at the estimation of the OBA effect, extrapolations included, this article is interesting to read. The attitude to declare UV cut measurements as dealing with the OBA paper content in practice is a false one, kind of ostrich head in the sand approach. Also notice that the estimation mentioned there improves when the non OBA reflection is already quite neutral, read "normal" whitening agents already created a flat spectrum without the OBA effect. Then the so called D50 measurement versus so called D50 viewing conditions and actual light sources used for both.
https://www.argyllcms.com/doc/FWA.htmlMet vriendelijke groet, Ernst
http://www.pigment-print.com/spectralplots/spectrumviz_1.htmMarch 2017 update, 750+ inkjet media white spectral plots