First I wanted to say that after your thoughtful reply I read the analysis you referenced in an earlier post. It was a very good effort. I could see where a lot of time and expense would go into a broader study. As example, one of the key details of interest to me is the effect of humidity upon paper aging. In this area we have high relative humidity. Over a year the average is between roughly 49% to 88%. Your test area was lower in this regard. I predict that a broader study that would show the results of the effects of differing humidity and temperature ranges would probably show some pretty pronounced variables. But I digress. I thank you for making this effort and also for sharing it!
> Hahnemuhle uses OBAs for the most part in their papers with judicious restraint and never puts any in the microporous coating layer only in the paper core. Hence, the amount of "yellowing" is not too pronounced as the OBAs begin to fade. Keeping the OBA out of the microporous coating makes a huge difference on susceptibility of the OBAs to light fade and gas fade rates.
Which illustrates that not only do not all manufacturers use the same amounts of OBA’s, but that there is a large influence upon stability which is based on manufacturing techniques.
> I'm not one who insists that artists concerned with print longevity must always avoid all papers with any OBAs (in fact some fine art papers without OBA will change paper color as well due to light bleaching), but I will tell you that the ultra bright white inkjet papers with lots of OBAs located in the microporous coating layers are very prone to OBA burnout in just a few years.
Agreed on all parts. In the event there was some ambiguity in my earlier comments, I'm making reference to OBAs used in a few types of Hahnemuhle papers.
> but who among us hasn't seen noticeable yellowing in the just a few years when using Epson Premium Presentation paper, formerly called matte paper heavyweight. Yet this paper gets 100+ year ratings in industry tests with Epson K3 inks. The simple reason is that the most commonly cited industry tests use a fairly liberal consumer tolerance for allowed paper yellowing. OBA burnout generally doesn't cause enough paper color change to trigger this consumer tolerance for failure, so it goes unreported
While I haven’t used Epson papers, you have made excellent observations and a thoughtful warning about the face-value of stability statements. You also hint that there is a degree of acceptance on the part of consumers for this process.
> and any serious collector or curator would notice the change.
Here is the crux of the debate. If prints are stated as made to the standards of serious collectors and/or curators then there would be a case of misrepresentation on the part of the artist. If the artist makes no claim of using museum quality materials, then your example consumers have nothing to complain about.
If someone approached me and said, does the paper you use have OBAs? I would point them towards the manufacturer's site for the particular paper. If they asked for a print using a non-OBA containing paper, I’d be inclined to do so with some minor warning about the differences the paper would produce. After all, one of the basic rules of customer services is to give the customer what they want.
> Simply put, bright white papers lose that pristine whiteness which was the basis for selecting them in the first place
Except that not all papers are bright white, and, as indicated, both the volume of OBAs and where they are used in the manufacturing process have a large impact. As a result, and as is nearly always the case, the simple answer is misleading.
> BTW, both FAP and PRP are among those HN papers that keep the OBA concentration to a minimum. They do pretty well in my light fade tests with OEM pigmented inks, although HN's OBA-free papers generally perform even better. HN Bamboo is an example of an OBA-free "naturally" warm color paper that light bleaches a little whiter in my tests with comparable change in paper color to some of the OBA containing papers. It just goes a little "bluer" rather than "yellower" as it bleaches.
I will be very interested to read of your other tests. If you’re okay with it, I’d like to link your web site when I complete mine.
Based on your recommendation, I'm also gonna get a roll or HN Bamboo.