Re: palladium drydown and developer

There was a minor amount of sub-rosa discussion bandied about among
some of the attendees of the last APIS about this issue. It was
stated at the conference by Mr King that these mysterious methods for
eliminating platinum drydown are two-fold: one method involves using
albumen as a sizing agent prior to coating, the other a similar
approach using collodion.

You may reasonably ask how these work. Well, I tried them. As you can
well imagine, the albumen provides a wonderfully smooth surface on
the paper for the sensitizer to slop around upon. When I tried this
at home using various dilutions of albumen 'subbing' on paper, I
found it messy and not all that effective. I also have questions
about the propensity for yellowing that albumen exhibits in every
true albumen print I have ever seen that has any years on it.

The collodion method proved very frustrating. The stuff is loaded
with ether and alcohol and went right through several of the papers
I was using, leaving me with more of a grease-o-type than a platinum
print.

Easy, simple, effective? Not in my experience. Admittedly, I did not
do an exhaustive test on every possible paper, but I did try the
papers I commonly use: Fabriano EW, Rives BFK, COT320 and Whatman's.
My assessment? Not worth the hassle.

I think the reputation for drydown in platinum comes from the tonal
scale being 'squeezed' from both ends. As others have pointed out,
the shrinkage of the paper as it dries brings image forming particles
closer together in the highlight areas, causing them to visually
darken slightly. The way to avoid this, again, as others have pointed
out, is to use papers that exhibit a lower degree of dimensional
change as they dry.

The other phenomenon that has not been mentioned is the microscopic
'fuzzing' of the paper surface that occurs as paper dries. This seems
to affect the dark shadow areas much more. It is really more
accurately called 'dry-up'. If you slap a wet pt/pd print on a
reflection densitometer, you will get a much higher reading (in the
1.8 range) than you will a few hours later after it has dried. The
tiny fibers of the paper then stand proud and cause a loss of
reflection density that in the best of cases will give you reflection
densities in the neighborhood of 1.4-1.5. This is almost a full stop
of reflection density loss.

As to what can be done to mitigate this effect, I have found that
very light gelatin sizing (in the 1% range) can help to a degree.
Another approach is to deal with this after the print is dry and
apply either wax or subsequent gum coats. I have a waxed vellum print
that has measured Dmax of 1.9 using several layers of Gamblin cold
wax medium.

My personal preference is for additional layers of expose gum, since
it offers so many options for color manipulation of the image.
Finally, a coat of Liquitex Gloss medium diluted 1:8 will also have
the effect of causing a measurable (though relatively minor half
stop) increase in Dmax. Again, I think this is because it causes the
microscopic fibers to lay down and behave.

One final method that I have heard mentioned but have not tried is to
run the finished print through an etching press and 'calendar' the
paper.

My two cents and experience with the issue,..

Clay

On Jul 21, 2006, at 12:59 AM, davidhatton@totalise.co.uk wrote:

> Dear Mr. King,
>
> I'm sorry but I must ask you. Why do you keep doing this? You drop
> into a thread
> hinting that you have some knowledge of the subject and then, when
> you are asked
> to substantiate your ideas, you start an argument. You also use
> every opportunity
> to sell some aspect of your business. You then have the audacity to
> tell people
> that they lay out data unfairly. Most people on this list help
> people freely. Why
> can't you? You agreed to post a single coat gum on your website
> which you have
> also failed to do. I personally, have come to the conclusion that
> you are all
> smoke and mirrors and that you bring nothing but strife and
> contention to this list.
>
> It's about time you stopped Mr. King. I don't have time for you.
> And do you know
> the worst thing? I feel betrayed by you.
>
> David Hatton
>
>
>
>
> ---- - Madasafish - Voted Best Heavy Consumer Broadband Provider in
> the 2006 Internet Industry Awards http://www.madasafish.com/
Received on 07/21/06-04:51:39 AM Z