Re: Pure pigments and gum.

I have lots of experience using dry powder pigments for gum printing.

I usually mix gum/pigment at a 1:1 ratio with an ammonium or potassium
dichromate solution. The ratio of pigment to gum will vary considerably.
Some pigments are very strong and prone to staining, e.g. phthalo blue which
I mix at 1 gram pigment to 130ml gum. Others are much weaker, requiring
considerably more pigment. I'm using burnt sienna mixed at 1 gram pigment
to 12ml gum.

Only thorough testing will determine the optimum ratio of pigment to gum.
Each pigment is different and requires individual testing.

Best regards,
Dave Rose
Powell, Wyoming

> Dear List;
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> Does anyone have experience with the use of pure pigment instead of
watercolors for gum printing?
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> I have done some testing with a mixture of pure pigment, gum and
dichromate - no additives.
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> The tests I have done until now shows staining problems.
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> Thanks in advance.
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> Roman Sokoler
Received on Wed Sep 1 07:29:53 2004