[alt-photo] Re: evaporation of gum mixture

[Paul Viapiano]

...or the water in the gum arabic? Of course, that must be it...

So can I just add water to bring it back to its original weight and be fine?

Paul



----- Original Message ----- 
From: "Paul Viapiano" <viapiano at pacbell.net>
To: "The alternative photographic processes mailing list" 
<alt-photo-process-list at lists.altphotolist.org>
Sent: Friday, July 02, 2010 11:51 AM
Subject: [alt-photo] evaporation of gum mixture


> Hello all...
>
> Having traced my pt/pd to a highly alkaline batch of Fabriano , I have 
> another question on an entirely different subject.
>
> Sometimes I make these little premixtures of watercolor pigment and gum 
> arabic, nice and handy for printing tricolors in the same pigments. I mix 
> about 1 gram pigment to 9 ml of gum.
>
> In May, I made a mixture and weighed it at 17.9 grams in its plastic 
> snap-cap container. Two months later, it weighs in at 17.2 grams. What is 
> it that is evaporating? Gum arabic? I'm curious...
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