[alt-photo] Re: Coating Silver Chloride - Non-Gelatin Based?

[etienne garbaux]

Francesco wrote:

>Can Silver Chloride and it's contrast agents
>be mixed purely in solution like Pt/Pl and coated directly to paper without
>making a gelatin emulsion like Mowrey teaches?

What you are describing is the "salt printing" process.  However, 
because silver chloride is essentially insoluble in water (and would 
just precipitate out if you tried to mix a solution of it), one does 
not mix the sensitizer and then coat it.  (This is what accounts for 
the fiddly part of gelatin emulsion chemistry -- getting the size(s) 
of silver chloride grains that you want, suspended in the gelatin solution.)

Instead, for the salt process (very simplified), you coat the paper 
with a salt solution ("salt" here being used in its generic sense, 
not necessarily sodium chloride), let it dry, then float it on a 
silver nitrate sensitizing bath, dry, and expose.  Note that you need 
to tone the image unless you are content with unattractive 
low-contrast reddish-yellow prints (gold and/or Pt are the most 
common toning agents -- I use gold followed by Pt to get a neutral black).

James M. Reilly wrote the definitive text: The Albumen and Salted 
Paper Book (1980, ISBN 0-87992-020-3).  It is available on the web.

Best regards,

etienne