Non-staining Blue for Gum?

FotoDave (FotoDave@aol.com)
Wed, 08 Apr 1998 21:17:08 -0400 (EDT)

I just made a gum print with black + thalo blue (I used Winsor blue but it is
the same as Thalo blue according to Wilcox). I like the hue. It is very
pleasing. However, since thalo blue is a staining color, it stains the paper a
little bit (well, quite visible, actually).

I think my sizing is reasonable because without the blue, the paper clears
completely (with Holbein Jet Black gouache). I suppose I could try different
sizing, but since I am not doing 3-color and the exact blueness is not that
critical, I think it would be easier if I can just use another blue that is
less staining (yet reasonably permanent).

Does anyone have any recommendation? Is ultramarine less staining? How about
Cobalt blue? Cerulean is so grainy that I don't know if I want to use it. I
guess I can go ahead and make different tests (since I do watercolor and have
different colors around anyway), but I would greatly appreciate any
recommendation or suggestion that could shorten the test period.

Dave