Re: Colors for Gum

SCHRAMMR@WLSVAX.WVNET.EDU (a.strauss@worldnet.att.net)
Wed, 11 Dec 1996 21:06:39 -0500

L. Shapiro writes,

> To all Gummists,
> I have been doing some multiple color gum prints (not 3 color prints
> just images where one tone is one color and another tone is a second
> color). I have noted that some pigments deposit a much stronger layer
> than others despite the dilution in the gum (or gloy) and dichromate
> being held constant. For example phthalo blue and pyrol red deposit
> very intense layers while greens, burnt umbers and siennas cover much
> less. Rowney's Jet black gouache gives a dark black but I'm not sure
> if its the pigment or the fact that it is a gouache. Some catalogues
> of water color pigments note that a particular pigment is transparent,
> semitransparent or opaque but I've not found this to be a useful guide
> in trying to pick pigments. The best test I've found is actually
> mixing up the pigment with the binder and the dichromate and making
> an exposure.
>
> What favor pigments, brands or types of paint are out there?
>

Larry,

I have had, of course, the same experiences with these pigments. I find,
generally, that the strength is more a function of color then the pigment;
that blues and reds are heavier then browns and greens. I find the best
results with good grade water colors and gouches.
Likewise, I have found that catalogue descriptions do not translate to
useful
specifications for gum application. I have,by trial and error, assembled a
personal set of *favorite* colors and use these. I just do multiple
printing
for colors that do not have adequate depth for my purposes.

Cheers

Al