Re: Transparency v semi-transparency

Katharine,
So here's what I found about Maimeri PY139.

I went ahead and painted the PY 110 M. Graham on black paper alongside the
PY139 Maimeri, (both isoindolines (sp) so I figured it might be a closer
pigment substitute to your PY110 than the other yellows, and in side by side
swatches of all the yellows I have, it is the closest match, along with M.
Graham's gamboge substitute.).

On black paper which approximates your testing on dark layers of gum the
PY139 is, in fact, slightly less transparent. On white paper I see very
little difference in transparency, though, exposed over marks below, except
there is one minor/major difference I do see: the Maimeri has a very faint
muddy green bias when exposed with dichromate. You may not see it unless it
is side by side with the same exposure of PY110, but in my opinion, PY139
Maimeri and PY110 M. Graham are close but no cigar. The PY 110 is as you
say a clearer color not only in transparency but in color bias as well. Too
bad M. Graham decided to dispense with it. Any other companies making it as
a stand alone pigment?

I suppose it isnt' the end of the world for me, tho, in that it is a bit on
the orangey side when doing a straight tricolor mix, and therefore I can use
more primary yellows in that scenario...

I'm off to photograph a bamboo forest...enough of this testing :)
Chris

(big snip from Katharine)
> PY 175 (benzimidazolone yellow) -- semitransparent
> PY110-(isoindoline) -- transparent
> PY 151 (benzimidazolone lemon)--semitransparent
> PY 3 (Arylide (hansa) yellow light)--semitransparent
> and PY 35 (cadmium yellow) --semiopaque
Received on Tue Jun 7 14:28:12 2005