On Thu, 12 Dec 1996 a.strauss@worldnet.att.net wrote:
> 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.
Al, that may be just coincidence, because generally speaking different
pigments have different covering power, irrespective of the color. For
instance thalo and indigo blue have very strong covering power,
ultramarine, less, cerulean and "permanent" blue less. Carmine has a
terrific covering power, greater than quinacridone red which it so closely
resembles (but is not, alas, as archival). Thalo green is quite strong in
a gum print, viridian green takes much more paint to give as intense a
tone. As I recall, Ralph Mayer lists covering power for the different
pigments, but I agree with you that how any pigment actually works in gum
& dichromate can only be found by trial and error.
Judy