Re: Yellow pigments and Gum problem(s)

On Nov 23, 2005, at 2:58 PM, roman sokoler wrote:

> Dear List
>
> I use Yellow (Schmincke PY154) ,

Hi roman,
Actually this pigment (benzimadazolone H3G, PY154) was also on Juan
Miguel's list of possible yellows from the other day, as Winsor &
Newton "Winsor Yellow" and I forgot to comment on it then. I've never
used this pigment, but from its description as a "light to very light
valued yellow" I wonder if it has the tonal depth to print the range of
tones that a darker-valued yellow might (it wouldn't have to be a deep
yellow, just a mid yellow would work fine). But then your statement
that it has the density you desire seems to contradict that idea. If
you're saying that the 7 indistinguishable steps are of sufficient
density, then that would seem to indicate a different problem
(overexposure, perhaps?) than if the 7 indistinguishable steps are very
light in value, which would seem to indicate that the pigment itself is
just too light (I'm assuming you've already ruled out simple things
like underexposure and that you're mixing the pigment at its maximum
strength). This is another case where it would be ever so much easier
to advise iif one could actually see the thing rather than trying to
guess from a description.

But this is starting to sound very much like a discussion from last
year. If you'll look in the archives for June, 2004, and find a thread
called "Gum Tricolor Yellow" you'll find a discussion that started out
by someone asking the very same question, (about a different yellow
pigment, PY138) The question brought out a lot of good discussion and
I think probably many of the same comments would apply here. So I'd
start by reading that discussion.

> Phthalo Blue (Sennelier PB15) and Quinacridone Red (Sennelier PR122)
> pigments for tricolor gum printing.

The only Sennelier paint McEvoy lists under PR 122 is called, according
to his listing, "quinacridone purple." The color index name for PR
122, in other words the proper name for the pigment, is Quinacridone
Magenta. I can't find my Page or Wilcox to check the Sennelier
listing, so I guess I'll just have to be puzzled about this
"quinacridone red" designation. I personally believe PR 122's
reflectance curve, with a significant peak in blue, doesn't make it a
good magenta for tricolor, but it also depends no doubt on what the
other two colors are, as well as on infinite other manner of things. Do
you find that this pigment works well for you?

Katharine Thayer
Received on Wed Nov 23 22:03:12 2005