Re: Test for Silver Metal in Print?

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Ender100@aol.com
Date: 10/28/03-04:22:05 PM Z


Sandy,

The only problem I can think of with calling a Kallitype that is PT/PD toned
a PT/PD print, it that the gentleman from Melon Museum's testing lab said it
would be a great help to any historian or people down the road who are trying
to determine what the heck a particular print is if the printmaker would be
very accurate regarding recording the process—this makes a lot of sense, since
you can imagine some future sleuth trying to explain the spectrographic analysis
of the print if some unusual metals showed up.... or a dab of mayo that
dropped from your sandwich during printing...

Mark Nelson
In a message dated 10/28/03 1:19:57 PM, sanking@CLEMSON.EDU writes:

> Hi Philippe,
>
> Thank you for your clear analysis of the possibilities and how to proceed.
>
> As to why I want to know this it relates to a comment made a few weeks ago
> by Judy Seigel regarding Pt/Pd toned kallitypes versus straight Pt/Pd.  What
> Judy wrote was this:
>
> Most casual photo purchasers probably never heard of kallitype, and even
> the "savvy" ones would probably confuse it with calotype.... Including the
> dealers. (If they actually know the difference they're probably
> photographers or historians and not in the market.) In any event, you
> might finesse the point by doing what the ancients apparently did... I
> doubt there is a non-destructive test to distinguish between the pd print
> & pd-toned kalli.... there may not even be a "destructive" test (???).
> Which is to say, the medium is what you say it is.
>
> This got me to wondering if there are any actual essential physical
> differences in a Pt/Pd toned kallitype and a straight Pt/Pd print. If there are not
> such differences, that is if they both consist of nothing but palladium and/or
> palladium metal on a paper surface, then my thinking is that it would indeed
> be appropriate to label a Pt/Pd toned kallitype as simply a Pt/PD print. In
> other words, if the two printing processes produce an image with identical
> tonal characteristics, identical physical properties, and identical archival
> properties there would appear to be no functional difference and we would
> merely have two paths to reach the same end.
>
> So the question is, of what does a Pt/Pd toned silver-iron print consist.
> Does it contain any free silver metal? And if not, has the silver been entirely
> replaced during toning, or has it been partially replaced and partially
> plated, or entirely plated.
>
> The answer to these questions would be important in evaluating the potential
> archival quality of kallitypes toned with the noble metals gold, palladium
> and platinum, and would also give guidance as to correct labeling. This would
> also have important economic considerations, especially for platinum
> printing, because if you could produce a print that consisted of 100% platinum metal
> with the iron-silver sensitizing method rather than with the iron-platinum
> method you would clearly save a lot of money. It takes about 1/5 as much of
> Pt/Pd to tone as kallitype as it takes to make a straight Pt/Pd print, and the
> difference is due to the fact that about 80% of the Pt/Pd used in coating is
> removed during processing.
>
> Let me make it clear that I am not making claims here, just trying to find
> answers. But at least I think I now understand how to find the answers.
>
> Sandy
>
>


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