Digital BW, The Print

Thanks Paul,

Right, it is wrong to group all rag papers with Ob's as being the same. That is a mistake a 
lot of us make. There are various degrees of OB content and chemical composition. Say if 
you compare Legion Matte or Hawk Mt. bright white Condor, or Red River Premium Matte, 
they all have a lot more brightening going on than say H. Photo Rag or Somerset or even 
Enhanced Matte.

I guess what still is unclear to me is the results of Wilhelm's tests with Somerset rag and
the Epson Watercolor media which both contain Ob's yet have excellent ratings that often 
exceed 100% rag media without any ob's present at all. These tests are supposed to reflect 
discoloration of the whites ( yellowing) as well as image fade. How much of this is the 
result of uv and how much is the result of air pollution is also not clearly established.  The 
Premier sprayed Somerset prints have super major improvements in his data. That is why 
when in doubt I spray. I really wish he would test Hahnemuhle media. I've written so many 
times to them and gotten no response. They know half of us out here are using Photorag 
and William Turner for fine art applications.

Go look at the  new test results on Henry's site for the Ultrachrome black and white 
process. He's uped the permanence estimates and in many cases far beyond what I'd ever 
imagined. And, I image Pauls inks beat these results because they are carbon with no color 
content at all.

John


-One reason I worry about papers with OBAs in them is that even if the paper
is archival, we know they will yellow as the OBAs burn out. I think this
will be seen as purchasers as a sign that the paper is cheap. If, for
example, the image was matted with a white border showing and is removed
from the matte & frame for storage after a few years of display, the
purchasers might see an outline of the matte board. It might look like a
yellowing and deterioration of the paper that was exposed to light. I don't
know how long it takes in typical display for this to show up, but it
clearly shows in my faded tests of, for example EEM.

Paul