Thanks Mark, I was hoping you would enter this discussion. It could be my instrument (XRite Pulse) is not picking up the OBA because it may be UV-cut; I'm trying to get clarity on this because when it was still current it had a UV cut/no-cut factory installed option. As I bought it second-hand I'm not yet able to get clarity on that detail. Do you have any reliable evidence to suggest differences of OBA content between the new and old IGFS? (BTW, that Pulse is still generating excellent profiles for me - my latest has an IGFS/4900 gamut volume of 977,000 and an overall dE of 1.07 measured from a print of the appropriately configured GM-CC.)
I don't have any of the latest IGFS in house. If you want to send me a small piece of your new versus old, I would be happy to measure and report back. I just stepped up to a new i!Pro2 because I want to update my tests to the new M1 measurement condition, and i need more speed than my old spetrolinos in order to deal with the new testing procedure I"m working out to track the LILIS issue.
Anyway, if you have papers high OBA papers like EEF in house, you can try reading them with your Xrite pulse and compare to the UV inc/UVexc data I list in the description page of each AaI&A test report. Also, you can cheack against Ernsts's spectrum vis measurements. This should help you figure out if your Pulse is UV excluded (M2) or UV included (older M0 condition like my spectrolinos).
Thanks for bringing the LILIS issue to our attention - one would never have known otherwise. Do you have any idea how long IGFS prints could remain in dark storage before signs of this trouble would become apparent? And what lusterish media on the market with roughly equivalent DMax and gamut would be free of this problem?
The stain can begin to form in just a few weeks after the print is retired to dark storage after sufficient light exposure on display. The extra staining can commence after there is any OBA burnout, so some will form in as little as 10 Mlux hours of light exposure, and it gets increasingly worse as light exposure dosage goes up and as more time in dark storage occurs. What makes things tricky about LILIS is that high intensity light sources can reversibly bleach the stain back to low levels, a good reason why conventional accelerated tests fail to discover the issue because the sample are usually measured immediately after the light exposure step. But the stain returns with further dark storage, so the bleaching effect is not a viable deterrent. There is a definite reciprocity law effect which clearly needs more study, but what I mean is that there is some light intensity level on display where the bleaching of the stain should match the low intensity generation of the stain. The bleaching affect is not a good solution or safe haven because it appears that at typical room display intensities, the stain generation out paces the light bleaching effect. Hence, we should be able to see the problem in real world samples, and indeed now that I know what to look for, I've got friends and colleagues finding real world samples! Fuji Crystal Archive II paper shows the effect, and I've seen real world examples with just 15 years on display at light levels of about 200 lux for 12 hours per day, a condition where this system would get an industry rating of 80+ years. Anyway, because the problem is related to OBAs and perhaps TI02 whiteners as well, it's not just an inkjet media issue. It is present in silver gelatin RC and traditional fiber prints that have OBAs present to varying degrees. Conservators probably assumed any stains in chromogenic color papers were due to bad processing or thermal stability problems with the residual color couplers, but LILIS is going to build unwanted stain as well.
If you want to avoid LILIS problems with glossy/luster type media, the best advice I can give for now is to stay clear of RC photo papers and non RC media with moderate or high levels of OBA. Use OBA free non RC papers like Hahenmuhle PHoto Rag Pearl, Canson Platine, etc. The RC media can build particularly high levels of stain (b* values of 15 to 25... that's yellow!). I suspect OBAs embedded in Ti02-PE layers is aggravating the OBA degradation and discoloration rate in the RC papers, but more study needed.
The yellowing can easily reach levels in some media that would certainly preclude sensible claims of 100+ year ink and media display life performance for fine art prints. Good examples of the LILIS problem can be found in ID#s 224 and 225 in the AaI&A database. These samples use HP's very stable Vivera pigments but were printed on two popular RC photo papers. The media can sadly become a very weak link in the system when high stability pigmented inks are used.
later,
Mark
http://www.aardenburg-imaging.com