Digital BW, The Print

>In my years of darkroom printing I don't recall people being 
>wound up at all about the presence or absence of brighteners, 
>except as a matter of aesthetics. We all knew that if you 
>washed brightened papers too long you could wash out the 
>brighteners, and that this would probably occur in an 
>uneven fashion, but no one that I know of advised 
>against using brightened papers for archival purposes.

I agree with the above.  Moreover, when I've put fiber-based silver print
samples in the fader, I've never seen evidence of significant yellowing.

>Are we being pickier than we (ie photographers) used to be, 
>or are inkjet papers more susceptible to degradation because 
>of "brightener breakdown"???

I was curious about this so pulled some silver prints from the files -- both
fiber based and RC.  I also pulled some samples of brightened and
un-brightened inkjet paper.  I help all of them under the UV light to
compare if they fluoresced.  The brightened inkjet paper "glows" under the
UV light, the un-brightened paper does not.  With the silver prints, the RC
glowed and the fiber based did not.

My memory is that the fiber based papers used titanium dioxide (TO2) as a
whitener that was referred to as a "brightener," but it does not appear to
be the same as the OBAs in the inkjet prints.  TO2 (or at least the paint I
have) does not fluoresce.  

When they put TO2 in the first of the RC papers, the result was cracking of
the polyethylene barrier caused by the free radicals that are catalyzed by
the TO2.  That is when, I believe, they started to use these dye-based,
fluorescing brighteners in RC silver prints.  However, I'd guess they only
used them in the RC prints, where they could be sandwiched between the
polyethylene sheets and not washed away.  As a dye, I think an OBA might
have been washed away very quickly in a fiber print.

They again, maybe in my silver prints they simply were all washed away.

At any rate, I did not detected significant if any fluorescing in the fiber
based silver print samples I've looked at under the UV light, and I have not
seen the significant yellowing of FB silver prints in fade testing.

Paul
www.PaulRoark.com