[alt-photo] Re: pigment problem

[Tomas Sobota]

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.

cheers
Tom

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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