Phalo blue is a colour which can stain easily if you overload the gum mix
it has a high tincture strength, I use it at 1+ 8 in my tempera print work
and do not have any problems as long as I do not go below that
dilution.Another tip is to print the blue last,then print a clear gum coat
with no pigment present ,this acts as a cleaning coat and will remove any
slight stain, however the paper must be correctly sized in the first place
for this cleaning to work efficiently, if the strain has penetrated the
paper fibre you stand no chance of removal.
>>I think my sizing is reasonable because without the blue, the paper clears
completely (with Holbein Jet Black gouache). <<
A slight black stain is hard to detect as the eye adapts through
simultaneous contrast effect and just does not see it unless the stain is
gross
>>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.<<
Manganese blue is a good substitute for Cerulean being a bright clear sky blue
and Antwerp blue is a nice violety blue
>>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.<<
It may be a pain Dave but don't cut the testing remember "If you wont to be
the best you have to test"
pete