U of S | Mailing List Archive | alt-photo-process-l | Re: pt/pd mounting

Re: pt/pd mounting



Now I'm just thinking aloud here, I've only made a few Pt/Pd prints under Kerik's supervision, so I don't claim to know what I'm talking about.

I was under the impression that it was the sensitiser and/or the development of Pt/Pd that was sensitive to alkalinity. After processing surely the paper the print is on is pretty much neutral after washing as everything including any acid pre-soaks are washed out? The resulting image is just the noble metal which is incredibly stable, one of the many reasons for using it.

So I guess using buffered or unbuffered board if fine, but like others have said an acid board, if it could be found or made, would be detrimental to the paper the image is on.

Does that make sense?

John.


www.johnbrewerphotography.com

Life shrinks or expands in proportion to one's courage. Ana´s Nin.




----- Original Message ----- From: "Gawain Weaver" <gawain.weaver@gmail.com>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, September 12, 2006 2:32 PM
Subject: RE: pt/pd mounting


Agreed, Liam. Although the issue at hand was buffered vs unbuffered
matboard, not buffered vs MDF. It's the situation of pollution coming
through the buffered board that would really give it a chance to react with
an alkaline reserve. However, if it is reacting, we then have to consider
how quickly the reserve will be used up. Also, carbonates will not react
with 100% of harmful gases coming through the board.

So if one is serious about the protection of one's photographs, it turns out
that environment is far more important than storage materials/enclosures.
Both in terms of temperature and RH to slow the reactions down and in terms
of keeping the nasties out-- peroxides, nitrogen oxides, etc. This also
applies to the zeolites and activated carbon that Hollinger mentions in the
link you posted. There is only so much they can adsorb before these
"molecular traps" become useless. That is not to say that they don't have
their place, but relying on them to protect your artwork over long periods
of time is asking too much of them.



And relative to polyurethane, I think this has come up before. Well
processed platinum prints last a very long time. Polyurethane coatings on
the other hand have no significant track record of permanence. And it
certainly won't be able to be removed from the print when it starts
deteriorating or delaminating. Do it if you like for artistic purposes, but
from a conservation standpoint it's a nightmare.


Gawain


-----Original Message-----
From: Liam Lawless [mailto:lawless@bulldoghome.com]
Sent: Monday, September 11, 2006 5:33 PM
To: alt-photo-process-l@usask.ca
Subject: RE: pt/pd mounting

Gawain, I'd suggest that a buffered board is definitely a good idea for
framed prints because anything (except light) that is going to harm the
print has to get past or through the board first. I've come across many
prints that have yellowed or stained because some idiot has used a frame
back of hardboard or MDF without an impermeable barrier between it and the
mount.


Liam

-----Original Message-----
From: Gawain Weaver [mailto:gawain.weaver@gmail.com]
Sent: 11 September 2006 22:06
To: alt-photo-process-l@usask.ca
Subject: RE: pt/pd mounting


There are several reasons why you might use buffered board.

1) All other things being equal, buffered board has greater permanence than
unbuffered board (this is why standards for permanent paper typically
include a requirement for a 2% alkaline reserve).
2) As Liam/Ware has mentioned it could potentially act to mitigate the
effects of the acid buildup from the catalytic action of platinum.
3) Buffered is generally cheaper
4) It won't do anything bad, so why not?

I would emphasize that the acid mitigation is purely in theory. Discussion
of pH and the buffering effect of an alkaline reserve should really be left
to discussions of solutions in water, not of carbonates in dry boards.

Gawain Weaver

-----Original Message-----
From: Camden Hardy [mailto:camden@hardyphotography.net]
Sent: Monday, September 11, 2006 3:02 PM
To: alt-photo-process-l@usask.ca
Subject: Re: pt/pd mounting

Katherine,

I apologize for the ambiguity of my question. You (and Liam) are correct;
I was in fact trying to find out whether acid board is good (as someone
once told me) or bad for pt prints.

My instinct was to say acid board is bad in general, but it was a fairly
convincing argument.

While we're on the subject though, what about buffered board? Can anyone
see a reason to use or not use it for pt/pd?

Camden Hardy

camden[at]hardyphotography[dot]net
http://www.hardyphotography.net





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