Digital BW, The Print

Robert wrote:

>The rather disappointing thing about the matte black ultrachrome ink is how
>poor it performs (dmax) on every paper other than EAM.

I don't get it.  Epson comes up with some hot new technology that raises the
bar for image permanence and blackness for a black ink -- but only on a
paper that Wilhelm says has so much acid in it that it turns unacceptably
yellow in 30 years.  Don't the paper and ink departments at Epson talk to
each other?

Speaking of EAM, I tried some of that Bookkeeper deacidification spray on
the back of some.  (It's sold by Light Impressions.)  It, of course, made
the back of the EAM very basic. ("acid free"?)  The problem is that the
buffer does not penetrate very far into the paper.  I was hoping my vacuum
easel would pull it deeper, but it doesn't seem to make any difference.  (I
use an acid test pen on the edge of a cut piece of treated paper to see how
far the deacidification penetrated the paper.)

I'm going to see if the maker of the product has any information of how far
the H+ ions migrate.  Part of the theory and reason these treatments do, in
fact, work in many applications is that the H+ ions (which are what acids
have that cause the damage) do migrate, and the damage they do to the
cellulose is a slow reaction.  On the other hand, when the H+ ions reach a
buffer the reaction is very fast, and the ion is captured and put out of
business.  So, I assume there is a relationship between the distance the
ions typically travel, and penetration of the buffer, and the effectiveness
of the treatment.  Hopefully the maker has this data and will share it.

>  I'm still hoping
>that the new Somerset paper has a EAM like coating on it ...

That would be nice.  The Somerset I have used just doesn't have the
smoothness of EAM that I like so much.

> I just coated an Ultrachrome print on Museo today.  The dmax went
>from a very poor 1.48 to silver-like 2.13 as measured by my spectrocam.

That's great.  Too bad Museo has a rough, grainy, blotchy look to me.

>...but then again you could also just print on
>Epson Luster.  The dmax is only around 2.0...
>but the prints still look pretty good.

Is that one of those "RC" type papers?

It is ironic that RC papers may be the best solution.  I wonder what the
interior of those papers is.  My reading indicates that lignin is not, in
itself, acidic.  It is only when it is attacked by oxygen and other gasses
that it breaks down into components that are acidic.  I wonder if the RC
papers can be relatively cheap but long lasting because they are sealed.

Shame I don't like the RC look either.  An acid-free EAM would solve a lot
of problems here.

Paul
http://www.PaulRoark.com