From: Judy Seigel (jseigel@panix.com)
Date: 04/04/03-01:25:16 AM Z
As a former watercolorist, let me say that I never saw ANYTHING in print
about "staining" pigments until something from a conservator's periodical
dated about 1995, which has floated somehow off my desk and into space.
When it floats back I'll cite specifics, but for now I note that it
divided "staining pigments" into L, M & H for low, medium and high
staining... but it only gave examples of low & medium... and as I recall
they weren't the ones we're talking about here & now.
Secondly, I suspect that Daniel Smith brought the concept into the
consumer arena -- I cannot remember seeing ANY reference to staining/non
staining in consumer printed material before the DS catalog started it.
3rdly, I note (sorry, I repeat myself) that the consumer literature I have
from WN, DS and Holbein, don't always agree... which figures because even
if they're RIGHT (which I doubt seriously), even nominally the same
pigment is possibly from different sources. (For one example, Daniel
Smith & Winsor Newton list cadmium red as staining, Holbein lists it as
non-staining. I didn't check Hilary -- too involved to cross check with
her. I find her organization disorganized.)
However, IME a primary factor in gum print "staining" is not mentioned
here... That is the particular gum arabic -- not the ratio or amount, but
the gum itself. I once did an exchange with another gum printer -- used
his gum arabic. It stained VERY heavily with most of my colors -- It
stained with SOME of his colors, but not all -- yet we were using many of
the same pigments -- leading to point that just the gum alone is not
overriding, rather the combo.
I've also found a difference in staining with my own gums, but not as
much, since I use the 2 or at most 3 that have been best. (Daniel Smith
lithographers, and the Philben house gum -- which is now RBP, which is a
great gum. Works very clean, and much lighter than the DS... or than the
DS was the year I bought it.)
Also,
On Wed, 2 Apr 2003, Katharine Thayer wrote:
>
> 2. Covering power: In my understanding, this has to do with opacity, and
> is a separate issue from staining. Covering power has to do with
> whether the color covers the color underneath, or not. In transparent
> gum printing, covering power is something you wouldn't want, because in
> transparent printing, particularly transparent printing involving
> different colors, you want the layers of color to shine through each
> other and blend into optical color blends. In opaque printing, covering
> power is a quality you would want, I surmise.
I don't find that covering power is ONLY opacity or even related
necessarily to opacity. I suspect in fact that a pigment could be opaque,
but have little covering power... maybe zinc white, and ivory black for
instance. How much bulk of it it takes to make a given or a strong tint is
also the sense in which Mayer uses the term... For instance thalo blue is
one of the strongest colorants I work with (only indigo is stronger, but
as I recall that's a blend of 2 or 3 pigments). Yet Daniel Smith lists it
as transparent & tho I haven't looked it up, I think "winsor blue" is
probably thalo & it's also transparent. I certainly find DS thalo
transparent in practice, using it for cyan in tricolor printing -- yet it
covers so strongly it takes less paint in the mix than others.
> 3. Lifting, which I understand to mean whether a color, when dry, will
> stay put when other colors are glazed over it, or will re-wet and mix
> into the subsequent colors in an unwanted manner, sometimes resulting in
> muddy color mixtures. IMO, this is not an issue in gum printing, since
> if properly hardened, the pigment underneath will not be disturbed by
> subsequent layers.
It's not really an issue in most watercolor painting either... the
"lifting" factor is I believe blown out of all proportion by books and
articles attempting to quantify everything to sell books & articles, or
eff the ineffable.
Which is to say, a wash can be put down over ANY color to not disturb
what's underneath if it's eptly done. And if it does pick up, that's nice
too. Really, I do think all this typing and labeling and sorting can make
watercolor painting into a grind -- an exercise in charting and math. And
the same for gum printing, actually. Makes it sound like much heavier
weather than it is. Scares off the multitudes. (Maybe that's good???)_
> 4. Tinting strength. In my experience, it's the pigments with the
> highest tinting strength that create the most potential staining
> problems for novice gum printers, and it's a matter of understanding
> that with these pigments, a little goes a very long way. But again,
> tinting strength and staining capacity are different issues; perhaps
> Christina can discover how the two issues are related to each other.
As noted, I don't find a connection between so-called tinting strength and
staining, except I suppose that if you use the paint weak and it stains a
little it will stain proportionately more as you use it proportionately
stronger. And as noted, I would tend to classify "tinting strength" if
classifying is necessary, tho I think it's being way way way overdone,
with covering power.
Judy
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