RE: An exchange with Mike Ware (on Argyrotype)

Thank you very much Mike. I think the issues are very clear now. That
was a great conversation. Thanks again for providing extensive
information.

Best regards,
Loris.

P.S. About vintage Kallitype & Vandykes; since our exchange concludes
with "given correct processing there's no reason for Vandykes /
Kallitypes being less stable than Argyrotypes or Salt Prints", I can't
see any other reason other than "incorrect processing habits".

-----Original Message-----
From: Mike Ware [mailto:mike@mikeware.co.uk]
Sent: 23 Mart 2006 Perşembe 14:17
To: Loris Medici
Subject: Re: An exchange with Mike Ware (on Argyrotype)

On 23-03-06 11:11, Loris Medici wrote

> I don't exactly understand your last sentence; you say you don't see a
> reason why properly processed - for instance, just as I described
> before
> - Vandykes (or Kallitypes) shouldn't be as stable as Argyrotypes, then
> you also say "but how stable that is, remains". Are you referring to
the
> stability of colloidal silver in general

Yes. When produced by iron-based processes.
Why have (almost?) no kallitypes or vandykes -apparently- survived for
100 years?

> or are you hinting that
> Argyrotype may still have the edge.

No, and again, no!

> If the latter, why? (This goes back
> to one of my guesses / speculations in my original question to you:
> since there's any silver nitrate dissolving effect over elemental
> silver, the particles may be slightly bigger in Argyrotype when
> compared to Vandyke -

I have no knowledge of, or information on, particle size determinations
in these prints, so cannot comment.

> therefore exhibiting less surface area to pollutants / oxidisers... On
> the other hand; since you said silver nitrate does so in acidic
> environment, Kallitype - which is developed in alkali environment
> - remains protected from silver nitrate's effect over elemental
> silver.)

But kallitype, as I understand it, is 'developed', whereas Van Dyke and
Argyrotype 'print out': processes which also tend to affect particle
size. In the absence of any known facts, these particle size arguments
are too speculative for me.

Best,

Mike

--
Dr Michael J Ware
20 Bath Road
Buxton
Derbyshire
SK17 6HH
UK
tel  :  +44 (0)1298 78604
email:  mike@mikeware.co.uk
WWW  :  http://www.mikeware.co.uk