[alt-photo] Re: pigment problem

Tomas Sobota tom at sobota.net
Wed Feb 9 08:57:17 GMT 2011

Hi Julian,

Well, it seems that the pigment problem is solved, but you still seem to be
having sizing issues. Why don't you just coat with plain gelatine and harden
later with a formalin solution? It is slightly more work, but you will never
have the problem of the gelatine hardening too fast. I apply two coats of 3%
gelatine and harden after they are well dry.


On Wed, Feb 9, 2011 at 12:20 AM, Julian Smart
<juliansmart at virginmedia.com>wrote:

> So I have now done a coat of Indanthrone PB60 on two seperate prints and
> found no problems whatsoever. I used a diluted pot. dichromate solution
> (6.5%) and gave my usual shadow exposure of 3 mins dead.  The pigment gave
> me a very nice split that I had been after, but curiously the prints  were
> effectively overexposed (enough that I could brush away the coating at will
> without destroying what I thought would be a very delicate layer).
> I am now of the opinion that the W+N Indigo paint I am using has a binder
> made from a gum that would effectively print much slower if I were using it
> for my main emulsion. The paint does seem to be slightly more sloppy than
> that from most other tubes, and I can't really imagine that the binder will
> have that much of an effect when mixed with my normal gum but I think I can
> now rule out paper sizing as an issue.
> I will record that I now have two very nice gumprints, both with the colour
> split I required but am still somewhat puzzled by the behaviour of the
> Indigo paint I originally tried.
> Julian.
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