Re: Yellow pigments and Gum problem(s)

Roman,
Would it help if you prined your yellow on top of a light blue insted of
white. Light yellow over white could be difficult to see the gradations.
Marek, Houston

>From: Katharine Thayer <kthayer@pacifier.com>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca
>Subject: Re: Yellow pigments and Gum problem(s)
>Date: Wed, 23 Nov 2005 20:02:08 -0800
>
>
>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 22:10:47 2005