At 05:47 AM 1/25/2000 -0800, Michael Greer wrote: >Gary, > >Where is this evidence? There are controlled lab tests that rate ink/paper for >longevity based on light exposure. But where is the evidence that concludes >that light exposure is more critical to print life than air exposure? You're defending what I'm not attacking--all I meant by "increased exposure to light will cause prints to fade faster" was the obvious-- more light, faster fading. >At this point, I believe there is a cross over point. Above certain light >levels (direct sunlight for example), light is the main culprit. Below certain >light levels (indoor non direct sunlight for example), air exposure becomes the >main source for fading. As a general statement, this would seem to be indisputable. After all, If the atmospheric conditions have any effect on print life at all, there is certainly some (sufficiently low) light level at which this effect will exceed the light effects. And it is clear that a sufficiently high light level can fade prints so quickly that other effects don't have time to do much. So my questions are: (1) are there effects on life from air exposure; (2) if so, what are they; and (3) at what levels do they become significant compared to light/UV fading? In my admittedly non-expert view,the answers are: (1) almost certainly [The 'almost' is only a minor hedge--maybe the inks fade due to reactions with the paper, regardless of air exposure. Has anybody stored prints in a vacuum yet?] (2) no idea--would appear to be a question for an environmental chemist or some such who could determine what attacks the dyes. Insufficient data. (3) Insufficient data again--but I don't think simple testing is going to prove anything until (2) is addressed. Without a hypothesis to test for, what we will know is what we know now--inkjet prints will fade to some greater or lesser extent even in the absence of light. If someone can establish, for example, that the fading is accelerated in the presence of moisture, or ozone (or sulfur dioxide, or name your poison), then it will be possible to do controlled testing that answers some useful questions in this area. Until then, what you believe is as good as (if not better than) what I believe. (In truth, I don't even disagree with you.) What we need here is a little genuine research--and somebody to pay for it. Is Epson listening out there? Gary Hunt <glh@srv.net> - Please turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for instructions.