U of S | Mailing List Archive | alt-photo-process-l | Re: Pigments for neutral color balance in gum: (Re: Fish Eyes again)

Re: Pigments for neutral color balance in gum: (Re: Fish Eyes again)

Thanks Katharine. Before dismissing PV19, I will first try using PB15:3 as
the blue. Since the spacing between PY42/43 and PV19 is fine (albeit in
the opposite direction of what McEvoy suggests; a yellow closer to the
magenta instead of a magenta closer to the yellow), and PB15:3 is right
opposite to them. If that doesn't give me acceptable results, then will
try with a brighter / colder yellow and a redder magenta. For the moment I
like PY42/43 because if gives nice / contrasty gradation gradations unlike
the brighter yellows (I simply can't see the gradations when printing with
a bright / transparent yellow).


17 Eylül 2008, Çarşamba, 5:38 pm tarihinde, Katharine Thayer yazmış:
> Hi Loris, sorry about taking off on a tangent.  I'm just guessing
> here, because I've not used that yellow (and would recommend using
> handprint's mixing triangle as an initial screen, as I suggest on my
> tricolor page) but I would definitely suggest a less blue magenta
> with your combination.   I've had good results with PR 175, a deep
> scarlet, with ultramarine and PY110, and Marek recently reported
> doing well with perylene maroon (PR179)-- which has a very similar
> hue to PR175-- with PY 150, which is also kind of an off-the-beaten-
> path yellow, and indanthrone, which like ultramarine, has more red in
> it than a true cyan.
>    It's a casual observation (I haven't done a careful study of this)
> that PV 19 is more likely to be implicated in those ugly purplish
> brown "neutrals" than other pigments;  I use it only with yellows and
> blues that stay pretty close to the pure primary hue.  Since the
> ultramarine is  redder than a true cyan,  you need a yellower red
> rather than a bluer red like PV19 to balance it,   and so forth.  The
> way I think of it is that in order to produce neutrals you need your
> three colors to be sort of equidistant on the color wheel, and if one
> is hue-shifted in one direction, then the others need to be shifted
> in the same direction.  Which is an implication of Bruce McEvoy's
> mixing triangle:  the triangle needs to enclose the center of the
> triangle in order to be able to produce a neutral black; if the
> triangle is way skewed from equilateral,  it may not contain the
> center (black) and  the three colors layered won't add to black.  If
> that doesn't make sense, then I need to find a way to write it better.
> Katharine
> On Sep 17, 2008, at 12:08 AM, Loris Medici wrote:
>> "PV19 -> strong paint" is a side note, irrelevant to the main subject
>> fisheyes... I use very little of this when compared to the other
>> colors
>> I'm currently testing/trying for tricolor (BTW, it occured to me
>> that it's
>> stronger than Ivory black). So far it gives me nice reds (when
>> combined
>> with Schmincke Yellow Raw Ochre 656 - a mixture of PY42 and PY43) and
>> violets (when combined with PB29 Ultramarine Blue). But I can't get a
>> neutral black with this combination (but brown). What other pigment
>> would
>> you suggest for being able to get neutral black in tricolor printing?
>> (Tricolor -> Cyan from Red, Magenta from Green and Yellow from Blue.)
>> Thanks,
>> Loris.
>> 16 Eylül 2008, Salı, 7:12 pm tarihinde, Katharine Thayer
>>>> On Sep 15, 2008, at 11:33 PM, Loris Medici wrote:
>>>> I have the same problem with the same pigment, Schmincke Ruby Red
>>>> 351
>>>> PV19. BTW, it's a very very strong paint... Do you think that adding
>>>> alcohol to the coating mix can help?
>>> Sorry, this doesn't make sense to me, Loris.  In the pigment lexicon
>>> I understand, strength of pigment refers to its mixing power (or
>>> layering power, in our case);   a  strong pigment needs to be used
>>> sparingly in order to keep from overwhelming the other colors that it
>>> is mixed or layered with.  In other words, with a strong pigment,
>>> you need to use much less pigment to get the same color intensity
>>> that takes more pigment to achieve with a weaker pigment.  (I'm not
>>> the first person to notice this; I recently came across a paper where
>>> Demachy was making the same point.)
>>> So if the PV 19 is a  strong pigment (in my mind, PV 19 is, yes,
>>> fairly strong as magentas go, but not as strong as lamp black or
>>> pthalo)  then it stands to reason that you should be using less of it
>>> to balance the other colors than you might use of a different pigment
>>> (PR 209, for example, requires a much larger amount of pigment to
>>> achieve the same effect) and I would think that it would be a mix
>>> that had more pigment in it that would require smoothing out with the
>>> Everclear, not one with less pigment.   Unless the purpose of the
>>> Everclear is to smooth out a watery mix rather than a more heavily-
>>> pigmented one.  Or unless you're meaning something entirely different
>>> by the term.  glad you're back, by the way.
>>> Katharine