Digital BW, The Print

>...I stumbled on a Krylon spray product which claims to 
>de-acidify anything on which it's sprayed.  
>Hmmm... maybe this would make cheap Epson Photo Paper more archival?
>Comments, Paul?

>See it here: www.dickblick.com/zz128/96/products.asp?param=0&ig_id=4427

I have had the same thoughts.  Here is where I'm at with this approach:

I suspect the Krylon product is essentially a private label version or total
rip off of Preservation Technologies' spray.  See http://www.ptlp.com/  

That product, sold also as Bookkeeper, uses a micron-size suspension of
magnesium oxide (in some form) particles that act as a buffer.  When sprayed
on paper, they stay on the surface of the paper.  The good news is that they
will not soak through to the image and possibly yellow it.  The bad news is
that the buffer is further away from the acids in the paper.

Wei T'o is the competitor.  They make a magnesium oxide (speaking roughly)
buffer that is dissolved in a solvent.  As such, when it is sprayed on the
paper, it soaks in.  This gets the buffer closer to the problem, but in a
fade test of a treated matte paper the paper yellowed more than an untreated
control strip.

So, I don't think the buffer should be allowed to hit the surface -- image
side -- of the paper.  This makes the dissolved version inappropriate for
matte paper, and the solid particles sprayed on the back are probably not
much more effective than the use a buffered back matte board.

On the other hand, the dissolved, Wei T'o spray on RC paper may be useful.
The inkjet RC paper is just resin coated on the image side.  So, the back
paper is open to the spray.  The polyethylene barrier then protects the
image side.  The images look good in my fade tests.  (Buffering does not
stop the photo-sensitive lignin from yellowing with UV exposure.)

So, cheap, artifact-free Epson Glossy Photo paper might also be made a bit
more archival.  But I still would not trust it all that much.  If the paper
has a lot of lignin in it, it'll take a lot of the buffer to keep it in
check for very long.  Some might be better than none, however. 

If you want things to last, I recommend you stick with "carbon on cotton."

(Then there is this Hahnemuhle coating yellowing thing.  You'll recall I
made curves for Arches Hot Press on the 2200.  Me, I use UltraSmooth [which
is probably PremierArt Hot Press] or PermaJet Alpha for archival uses.  I
like a light spray of Lascaux for more protection.)

Paul
www.PaulRoark.com