Digital BW, The Print

Hello Frank,

>What does one do if one wants to print neutral prints and wants to 
>have them keep the tone. Should they be printed on papers with no 
>OBA's, acid etc, and just live with the warmer tone of the 
>non-whitened paper or is there an alternative.

There is a widely accepted assumption that any paper with OBAs is
going to yellow.  But experience shows that that is not necessarily
true.  There are different kinds of OBAs, they are applied in
different ways and in different amounts according to formulas that
paper makers don't divulge.  There's a huge amount we don't know, so
we have to judge each paper individually.  

Two of the most popular and best dmax matte papers, HPR and VFA, have
OBAs.  Hahnemuhle has stated that HPR has just a tiny amount of OBAs
in the coating to ensure uniformity across batches (or something to
that effect).  I've never seen any OBA data about VFA.  Technically
HPR has OBAs, though in miniscule amounts.  Should that paper be
judged the same as one with greater amounts?  I did some research on
this a couple of years ago (please see the the OBA part of article #5
at the link below for details).  Paper makers and vendors told me that
they feel the OBA issue is overblown.

Diana York of Hawk Mtn papers said their paper fibers are white to
begin with, so any OBA "burn off" doesn't result in yellowing, only a
slight lessening of brightness.  My own tests with Condor BW, one of
their bright white papers, has borne this out.  Prints that have lain
around unprotected for several years, some getting bright daylight
and/or fluorescent light exposure, look only slightly less bright next
to a new sheet, and no less white.  Same for HPR and VFA prints and
many others I've tested over the past 5+ years.  EEM is the only paper
I've experience any real yellowing with.  I've never seen any hard
test data saying that HPR or VFA yellowed by X amount over Y time with
Z amount of exposure, etc.  From my reading it seems they are more
likely to yellow from exposure to chemical fumes than anything else.

It's possible they do yellow slightly over a long period of time, I'm
not saying they don't.  But HPR has been in use for a long time, and
during the almost 6 years I've been involved in this I have never once
seen a print with, heard an actual complaint of, or read scientific
evidence of OBA-related yellowing. 

A question I have is why use them if they're in such small amounts as
to make almost no visible difference when they burn off?  I suspect
the answer is marketing realities: without them their paper would look
dull next to their competitors.  Most people comparing samples would
choose the brighter paper and they'd lose market share.  Also, as H.
stated, they want uniformity across different production batches. 
Just think what kind of reviews HPR would get if one batch looked
different from another.  Over time the prints change ever so slightly
and slowly and nobody ever notices.  That's just a guess, but I bet
it's not far from the truth.

Bottom line is we don't know what kind or how much OBAs are in any
paper.  If this bothers you then you'll just have to avoid using OBA
papers (but you'll miss out on some of the best).  Not all non-OBA
papers are "natural" colored.  In article #5 at the link below have a
look at the Innova non-OBA papers.  Their color is very much like HPR
and VFA, somewhere between pure white and "natural", really beautiful
papers (but less dmax unfortunately).


>Also, does this yellowing happen with lustre papers or just with 
>mattes.

I have little experience with the glossy papers so I can't comment. 
My feeling though is that the same principles apply: judge each paper
individually.  If a paper has OBAs then look for real evidence of
yellowing (hard data, user reports, whatever) and base your decision
on that.  I use HPR, VFA, Condor BW and others with confidence because
they are widely used, have been around a long time, and I've yet to
find any evidence of their yellowing.

(also please see my similar OBA post of July 6, 2007)

Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm