Digital BW, The Print

Todd Flashner wrote:

> on 11/12/01 11:28 PM, SKID Photography wrote:
>
> > The latest studies show that the buffering agents react very poorly with
> > inkjet inks and should be avoided if
> > one is looking for long term paper/print stability.  Just as one should avoid
> > optical brighteners.
>
> Harvey
>
> Could you elaborate on what you know about optical brighteners being
> detrimental to inkjet prints? As I understand it (which is not much) the OBs
> fade and the paper will yellow, but is it anything more detrimental than
> that? The papers which don't have OBs are already somewhat yellow, so I'm
> not sure you'd any worse off with OBs down the road. The non OB paper would
> always be warm while an OB paper would creep "white" to warm.
>
> What I suspect has the greatest impact on longevity is the coatings of these
> papers, but they gets little discussed. Anybody have any way to comprehend
> their impact on our prints?

Todd,
My understanding on all of this is limited, and what I know (beyond my old museum and photography experience
memory) comes from the paper:  Stability Issues and Test Methods for Ink Jet Materials, Barbara Vogt,
Department of Image Engineering, University of Applied Science, Cologne.  The url, where the 62 page pdf can
be downloaded:
http://www.geocities.com/mortenryhl/index.html

That said, I think that degraded optical brighteners are yellow, but that the high end, non brightened papers
are more 'creamy' (not yellow).  And that most papers that are brightened do not start off as bright as the
high end 'archival' papers (like Museo or Epson Smooth Fine Art).  And *that* would lead me to believe (and
this is total supposition on my part) that after the OBs degrade, the resulting base paper would be less
bright than the high end ones.

As far as your suspicion that the coatings are the 'weakest link' in image stability I'm not sure.   The whole
stew of acids, paper pulps, coatings, pigment vs. dye inks, humidity, light exposure, heat, ink particle size,
buffering agents, ink colors reacting with one another etc. all enter into the mix....Scary monsters!

Check out the thesis above, it's very interesting.  What I really got out of it was that no one knows yet, but
that soon, more will be revealled.  Frustrating, yes.  But...It's all new technology.

Harvey Ferdschneider
partner, SKID Photography, NYC



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