Perhaps the pH of the ferric is well suited for PD but not for PT. Or the
paper does not support a mix with the PT. You may also find that letting
the coating solution sit for a while before coating helps. Rather than mix
the solution and coat immediately, a slightly mature solution may work
better. Are you drying the well before humidifying? I have been using a
50/50 mix with no problem.
Eric Neilsen Photography
4101 Commerce Street
Suite 9
Dallas, TX 75226
http://e.neilsen.home.att.net
http://ericneilsenphotography.com
> -----Original Message-----
> From: FDanB@aol.com [mailto:FDanB@aol.com]
> Sent: Sunday, May 16, 2004 9:37 AM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Streaming with pure Pt on Cot 320
>
>
> Wanted: suggestions as to why a 3:1 ratio of pd:pt makes a great print
> but the same neg printed with pure pt suffers from either weak blacks
> (when single coated) or streaming (migration of metal into highlight
> areas) when double coated. Here are the specs:
>
> Paper: Bergger Cot 320
> Ferric: fresh stuff mixed from B&S powder (fresh but aged several days)
> Developer: Potassium Ox. at 110F.
> Paper humidified before and after coating
>
> I don't plan on printing with straight pt myself but was tyring to help a
> friend when we encounted this problem.
>
> Many thanks in advance for any helpful advice!
>
> Dan
Received on Sun May 16 11:14:49 2004
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