Digital BW, The Print

Seth,

>...  What about Epson double sided matte?  It
>encapsulates the paper (okay, not the edges) with the coating.  But,
>wouldn't it be inherently more stable.

I don't think inkjet coating is the type of encapsulation that gives any
kind of protection against, for example, air-borne pollution.  I fact, the
opposite might be true.

Also, if acidic paper is encapsulated, it deteriorates faster than if it is
not encapsulated.  The acids form H+ ions that migrate.  If an acidic paper
is open to the air, some of those ions will simply migrate out of the paper
before doing any harm.  If the acidic paper is encapsulated, all the ions
are trapped and eventually attack the cellulose fibers.

>Heck, it seems there are recycled papers out there that may be
>less acidic for a base layer.

The only analysis I've seen of EAM paper base indicated that it was not a
poorly made paper.  It just is not buffered.  Since calcium carbonate
buffering is cheap, I think there must be a reason Epson did not buffer the
paper.  It probably relates to some aspect of performance -- gamut is what
I've read, but this was not from Epson.

In the tests with deacidification I've done to date, post-printing
application does not seem to affect dmax or fading.

The pre-printing buffering experiments I've done have been a mess.  If
calcium carbonate gets on the rollers, the paper feed appears to be
negatively affected.  I wonder if buffered papers are usually double coated
to stop this?  If so, this is surely a cost that Epson might want to avoid
to keep the cost of the paper low.  Epson's beta Ultra Smooth Fine Art is
also double coated, by the way.

>My initial reaction, though, would be back to the
>Epson "mount it" routine.
>Then, I'd use an acid-free (NOT pH neutral) backing board.
>Not really osmosis, but they should have a reasonable
>neutralizing effect on each other.

A buffered backing does catch those migrating H+ ions.  The Preservation
Technologies spray works on that principal.  It just stays on the back of
the paper, and the hope is that the migration rate, paper thickness, and
speed of acid attack are such that the buffering catches most of the H+ ions
before they do damage.  The acidic attack on cellulose is slow.  The action
of a buffer is almost immediate - but only when the migrating ion gets close
enough.

Preservation Technologies was going to test their product on EAM.  I will
give them a call to see whether they have done it yet.

Paul
http://www.PaulRoark.com
______________________________________
=-----Original Message-----
=From: Paul Roark [mailto:paul.roark@...]
=Sent: Tuesday, February 18, 2003 11:49 AM
=To: DigitalB&WPrint
=Subject: RE: [Digital BW] EEM/EAM Deacidification -- Wei To spray #12
=
=
=Seth,
=
=>One thing troubles me about the soak-in spray.  I guess the
=analogy is
=>paint peeling off the side of a house. It is caused from moisture or
=>oily stuff getting behind the paint. With water it just blisters off
=>from the vapors; with other substrates, it just refuses to stick.
=
=>Do you see this as a problem?  Is there any way to test for it?
=
=I'll do what I can to test the product before actually using
=it on a print that matters. It's too early for me to know.
=
=The solvents are denatured ethyl alcohol, tetrafluoroethan,
=and 1,1-dichloro-1-fluoroethane.  Not being a chemist, I have
=no idea what all the characteristics and risks of these
=solvents are.  It seems to evaporate very quickly.  I think
=the idea is to leave no residue except the buffer -- basic
=magnesium carbonate.
=
=The product is made to be used on papers with ink and
=colorants, but I'm sure there is some risk that the solvent
=could affect something.
=
=>...archival and de-acidified storage usually also mean
=encapsulation in
=>Mylar and dark storage in a controlled atmosphere.
=
=I'm just trying to deal with the major defect that has been
=identified with EAM/EEM.  I think very highly of the paper,
=but acidity of the paper base has been identified as the
=factor that will yellow it relatively quickly (30 - 60 years),
=no matter how carefully it is stored.
=
=In my actual dealings with old photos and digitally restoring
=those images, the physical damage to the image from careless
=handling, insects, water, and other environmental factors is
=far more of a problem than the fading of the images or acidity
=of the old paper.  (We're not talking about low quality
=newsprint paper that does seriously yellow and  deteriorate in
=rather short
=order.)  So, I would agree that even if totally acid-free,
=protection from environmental damage is critical.  At some
=point I'll have time to get back to the coating issue, which I
=think holds some promise of helping to protect the fragile
=inkjet images from physical damage.
=
=I'm sure people who are primarily concerned with long-term,
=archival storage will also insist on cotton.  I have some
=reservations about cotton substrates due to the flaking of the
=coatings.  I think the soft cotton substrate makes the flaking
=more of a problem.  (A thin coat of clay on a pillow comes to
=mind.)  Epson's Ultra Smooth Fine Art is their latest effort
=to make a cotton paper that does not flake.  So far, I see
=none with it, and may use it for the museum reproductions.
=But for my display images where image quality and my
=out-of-pocket cost for large size paper are significant
=factors, the post-printing deacidification spray could be a
=good compromise.
=
=Paul
=http://www.PaulRoark.com
=_________________________________
=
==-----Original Message-----
==From: Paul Roark [mailto:paul.roark@...]
=
==Subject: [Digital BW] EEM/EAM Deacidification -- Wei To spray
=#12 = =show yellow with my Abbey test pen. = =I just tried the
=Wei To spray -- #12.  It appears to soak into =the paper. One
=slow sweep of the spray across the back is =enough so that the
=interior fibers are testing non-acidic =throughout the paper.