Digital BW, The Print

Ed,

>Does anyone have an educated guess as to how long the print life
>might be using the new UT or UT2 inks on some of the more popular RC
>papers?  I'm thinking maybe Epson Premium Luster Photo paper or maybe
>some of the Ilford papers.  ...

I'm one of the many wet darkroom B&W printers who got burned by the early,
over-optimistic claims of RC print stability.  Despite early claims, they
turned brown and bronzed badly in many display situations.  So, I have a
basic distrust of "RC" technology.  I still believe that for the ultimate in
inkjet longevity, "carbon on cotton" is the safest bet (under glass or
protected someway).

That said, I have now heard and read enough to think that *maybe* the modern
RC/"barrier" papers can really be very long-lived -- a necessary ingredient
of my interest in medium.  

First, Kodak, one of the companies burned by the early failures, has taken a
strong stand in favor of the technology.  See
http://www.kodak.com/global/en/professional/support/techPubs/o3/O3wp4.jhtml#
1274467 
for the details, but the basic story is that the problems of the early RC
papers were found and cured.

Kodak's current conclusion is: "The best scientific estimates of the
comparative life expectancy of RC and fiber-base prints show little
practical difference. Both will last for a very long time under reasonable
storage and display conditions." 

Second, my chemist brother claims the "polyethylene" (the coating on the
paper) is a very broad category with many variations.  Thus, the current RC
plastic coatings might be very different than the older ones.  As we know
from the problems of plastic in the environment, it can last a very long
time and be very non-biodegradable -- much more so than cotton.

Third, and most important from a marketing point of view, Wilhelm tests --
both accelerated fading and paper life accelerated aging -- have shown the
Epson Premium RC papers to be very good.  See
http://www.wilhelm-research.com/ at the "Epson 9600 (UltraChrome) link.  On
page 3, Wilhelm lists the "B&W" display and dark storage ratings.  Since the
UltraChrome "B&W" (not IP5) has much more color in it than the Ultra Tone
inks, the ratings of the UT & UT2 inksets would, I believe, be substantially
better than what is shown.  (The carbon pigments are substantially more
stable than the color pigs -- the less color used, the longer the life.)

The Epson Premium Semigloss and Glossy prints framed with UV class have
display lives of >150 years.  Only UltraSmooth exceeds this.  The Premium
Semigloss and glossy papers have dark storage lives of >200 years, which is
how Wilhelm rates the best cotton papers.

Displayed without any protection, the Semigloss falls to a 74 year display
life.  How much the PremierArt spray with its UV protection affects this
life is unknown.  I'd guess that it would end up somewhere in between --
still not a shabby performance at all.

Note that the Epson Premium RC papers are the only ones where I've found the
internal paper appears to be neutral.  Ilford and the cheaper Epson RC
papers test with my Abby acid test pen as having acidic internal fibers.
Ilford claims that it's Smooth RC papers have a life of at least 30 years.

In the real world, air pollution, oxidation, and physical damage are huge
factors.  Encapsulation of the image in a way that protects if from these
factors may be more important than ultimate paper life for most of our work.
Despite what the conservators may want, in the real world the dry-mounted
silver prints (on acid-free board) are lasting longer than non-mounted
prints, apparently due to the barrier that the dry-mount tissue puts behind
the paper and the physical protection offered by the board.

So, right now, the potential of the sprayed Epson Premium Semigloss
RC/Barrier-paper print looks pretty good to me.  (I've also recently
dry-mounted a few them, which appears to work very well.) 

Paul
www.PaulRoark.com