Re: Yellow pigment stain: (Was: Re: Sodium Bisulfite

From: Katharine Thayer ^lt;kthayer@pacifier.com>
Date: 08/25/04-09:35:08 AM Z
Message-id: <412CB1AA.A30@pacifier.com>

Katharine Thayer wrote:
>
> gdimase@hotmail.com wrote:
> >
> > Yes, I always use 2 grms of pigment with 6 cc of gum arabic and 6 cc of
> > potassium dichromate and everything came from the same bottle and the same
> > tube.
>
> Then I'd agree with Judy that the pigment stain may be related to
> sizing. But I hope you don't mean that you always use the same amount of
> pigment even with different pigments; doing that will give you very
> uneven results. The amount of pigment should be adjusted for the
> particular pigment, as different pigments (and different brands of the
> same pigment) vary widely in pigment strength and in how much pigment
> there is in the tube.
> Katharine

In fact, this is more crucial in tricolor than in any other kind of gum
printing. You need the three colors to be equally saturated if color
balance is important to you (and I got the idea from some earlier
threads that it is) but to get the same saturation with different
pigments takes different amounts of paint.

I'm still thinking about some threads I saw a couple of months ago where
someone was trying to find out how to get the negatives exactly right to
make a perfect tricolor. I think that's a wild goose chase, personally.
I've made tricolors from many different kinds of negatives without
spending a lot of thought on it; the key to tricolor is less in the
negatives than in the printing itself; it's the skill in printing that
determines the success of a tricolor gum print, IME.
Katharine Thayer
Received on Wed Aug 25 16:31:15 2004

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