Re: Jon Edwards Print Humidifier Prototype

From: Dan Burkholder <fdanb@aol.com>
Subject: Re: Jon Edwards Print Humidifier Prototype
Date: Thu, 04 May 2006 14:13:46 -0500 (CDT)

Thanks, now this one is in plain text.

> I'm new to the glycerol-sorbitol enhancement but it sounds like a good
> thing to try.

I've been suggesting this technique from time to time when I see
humidity issue discussed on this list. Glycerol and sorbitol are two
examples of humectants that can be mixed with many photographic
solutions in small quantity.

> Of course, those coating additives would only help moisten paper for
> the exposure part of the printing regimen and wouldn't address the
> desire to humidify virgin paper to slow absorption of the
> sensitizer. Just a thought.

In that case, you can spray (or brush or soak) the paper with a dilute
solution of glycerol before coating. It's probably helpful if you
incorporated a small amount of PhotoFlo or other wetting agent in it.

Glycerol will wash out in the postexposure rinsing steps so there
won't be residue once processed.

In gelatin based processes, larger sugars and sugar alcohols are often
used so that some of them remain in the gelatin matrix after
processing, so that the gelatin does not become too brittle. In
binderless processes, this is probably irrelevant.
Received on 05/04/06-01:34:59 PM Z