RE: Silver chloride contact printing papers - not AZO

Thanks, Etienne, that could be very useful. A few warm-tone papers used
to give good print-outs straight from the box - Kentmere Art Classic and
Kentona are a couple I remember; I think Oriental Seagull was another.
But that was maybe 10 years ago, and I think many paper emulsions have
been "revised" since then. How would you describe the images you get on
Azo and Kodabromide?

Liam

-----Original Message-----
From: Etienne Garbaux [mailto:photographeur@softhome.net]
Sent: 29 January 2004 02:58
To: alt-photo-process-l@sask.usask.ca
Subject: RE: Silver chloride contact printing papers - not AZO

> Judy wrote:
>
> I'll add, though that DOP can be made into POP with a chloride
> bleach... I think Chris Anderson, or maybe it was Liam, or both(?)
> have done that too... You bleach it back with hydrochloric acid & (as
> I recall) a bichromate bleach... and just leave it in the sun or
> strong light and forget about it... You think nothing is happening,
> but in a few days you have a brown tone quite tactile photograph.
> Could probaably gold tone it too, if you felt the urge.
>
>
> Richard Knoppow wrote:
>
> Somewhere, in the all too distant past, I also had instructions for
> making POP out of DOP. Mainly I remember that it was treated in a
> solution that included silver nitrate. I can no longer remember where
> I saw this but have a vague clue that I can follow up.
>
>
> Liam quoted L.C. Clerc and elaborated:
>
> Well, I tried once with 0.5% silver nitrate and (probably) a
> chlorobromide paper. As I recall, the silver bath had no effect at
> all, compared with an untreated sheet. As I understand these things,
> the free silver nitrate permits much greater image densities from
> printing out, by combining with the halogen liberated by light
> exposure of the original silver halides to form more silver chloride
> or bromide as printing proceeds. I'd hazard a guess that the problem
> is that the original silver salts of the development paper just aren't

> sensitive enough to UV, their speed in this respect (I guess) having
> been determined by the emulsification process. Maybe develop-out
> papers were different in Clerc's day, but it might be interesting for
> someone with time on his (her?) hands to try again with a developer.

Maybe the Clerc recipe is a typo. Think albumen. I have had acceptable
to good results using AgNO3 solutions in the 5% range, usually with a
bit of citric, tartaric, or acetic acid. Float the paper (emulsion
down, for those of you not familiar with salted paper or albumen), don't
immerse it. Make sure you use "real" DOP, not the developer-incorporated
stuff that so often passes for photo paper these days. I've used
Kodabromide (sadly,
discontinued) and Azo successfully this way.

Best regards,

etienne
Received on Wed Jan 28 21:40:54 2004