From: Katharine Thayer (kthayer@pacifier.com)
Date: 09/20/03-11:50:44 AM Z
Okay, I agree that it was probably abrupt and rude of me to respond to a
post without reading the whole thing, but given that the entire post
appeared to be based on a complete misconception, that I had confused
two pigments, indanthrone and indigo, I wasn't inclined to read further.
I have now taken my punishment by hauling it out of the trash and
reading it to the end; there's nothing there to add to what I got from
the first paragraph. There's just a lot of irrelevant information, none
of which is new to me, and none of which explains why Judy keeps
insisting that I've got indanthrone mixed up with indigo.
The nearest I can speculate how this misconception came about:
I said (correctly) that the convenience mixture that Daniel Smith
packages in a paint they call "indigo" is a mixture of indanthrone
(PB60) and lamp black.
To say that a PAINT named "indigo" is made using the PIGMENT named
indanthrone is hardly the same as confusing the PIGMENTS indigo and
indanthrone, but it appears that Judy somehow made the logical leap
from paint to pigment and chose to interpret that disconnect to mean
that I had mistakenly equated the two pigments. In that case, why not
be consistent and also accuse me of confusing indigo with pthalo blue
and with Prussian blue, since I also listed convenience mixtures called
"indigo" that contain those blues?
(I didn't get the information about Daniel Smith's paint from any book
source, BTW, but straight off a tube of Daniel Smith's "indigo" paint,
and all this stuff about what all the different sources say about indigo
and indanthrone is just totally irrelevant, since no one but Judy has
ever confused the two with each other.)
The "real" indigo was actually made from the inksacs of squid, and
Judy's right that it hasn't been used in paint for a long time, but that
has nothing to do with this discussion. The indigo that is still used
in some paint is a synthetic indigo that's been in paint since the late
1800s, and its pigment name is indigo. And it has nothing to do with
indanthrone.
I kind of think Judy's got indigo mixed up with "indanthrene" whatever
the heck that is. ;-)
I apologize for testing the patience of the group, but when
misinformation keeps being repeated, especially when refers to me
specifically, it seems important to set it straight.
Katharine Thayer
Judy Seigel wrote:
>
> Sorry I didn't get back on this sooner, but reality intervened, as it so
> likes to do. I return to the point, however, because the longer the world
> believes that Indanthrene is indigo, the harder the notion will be to
> dislodge from the collective brain and the more it will defy correction
> (as per the so-called Gum Pigment Ratio test which, after 3/4 of a
> century, WILL NOT DIE!).
>
> I assume Katharine got the notion that Indanthrene is indigo by surmise
> from, or even assertion of, a recent watercolor pigment book, the title of
> which I forget, by a woman whose name I also forget, although it is surely
> not 20 feet from where I sit, possibly under a piece of laundry or other
> loose detritus (proving again, if proof be needed, that it can take an
> instant to put something "away" & a lifetime to find it).
>
> But I beat about the bush, sorry. (I'm rattled by this loss & if someone
> will kindly tell me the wording of the title, and the color and dimensions
> of the book, I'll try again.) Meanwhile, I refer to Mayer, Doerner, Wilcox
> and Delamare & Guineau on the topic. I said "real Indigo is no longer
> available," or wowrds to that effect, nor is it.
>
> To quote Ralph Mayer (whose "The Artist's Handbook" was the bible until
> acrylic took the field), indigo was,
>
> "A deep transparent blue originally obtained from plants cultivated in
> India. A better grade has been made synthetically from coal tar since the
> end of the 19th century. It is not entirely light proof & has long been
> discarded as a permanent artists' color. [Indigo] was used in Europe from
> early times, principally as a dyestuff."
>
> My copy of Mayer, dated 1957, does not mention Indanthrene, although my
> Doerner, dated 1940, does, leading me to surmise (perhaps falsely) that
> Indanthrene was a product of the German synthetic dye & pigment industry,
> which prevailed in the early 20th century until it was discombobulated by
> WWI. When I painted in oils, Max Doerner's "The Materials of the Artist &
> Their Use in Painting with Notes on the Techniques of the Old Masters"
> drove me crazy for digressivity and lack of clarity, seeming not quite
> translated from the German. But now that I'm not trying to learn
> undercoats, grounds & sizing, et al, it seems just pleasantly chatty.
> Doerner calls natural indigo "impermanent" and "entirely superfluous." His
> brief comment that "at least today" we have "Indanthrene blue GGSL for
> Prussian blue" suggests that the color was relatively recent.
>
> My 1991 Wilcox "Guide to the Finest Watercolour Paints" spells it
> Indanthrone, color index name PB 60. "A slightly dull blue, leaning a
> little towards violet. Semi-opaque, it has poor covering power unless
> applied rather heavily." He rates it ASTM I in both oil & acrylic, but,
> "without the binder it might not rate as highly in watercolour."
>
> Wilcox also says "genuine Indigo" is now obsolete in artists' paints. A
> synthetic version introduced in 1897, PB 66, "deteriorated badly." It's
> also called "CI Vat Blue 1 Dye." He shows 13 contemporary brands of
> watercolor paints NAMED "Indigo." Most with good ratings are based on
> thalo; only one is based on "Indanthrone" -- from Lefranc & Bourgeois. It
> rates 3 out of a possible 4, & II for lightfast (I is highest). I assume
> the ones Katharine cited are later developments, or otherwise omitted from
> this Wilcox.
>
> But if you've read thus far, reward yourself with a wonderful little book,
> "Colors: The Story of Dyes and Pigments" by Francois Delamare and Bernard
> Guineau, only $13 from Kremer [Discovery/Abrams], charmingly illustrated
> in full color, a gem for the library of any artist. It leaves us in humble
> awe of the achievements of artists whose colors were brought by caravan,
> trader, shipwreck and warlord from India or other remote sources, then
> excruciatingly processed. We learn why colors acquired certain uses and
> meanings, and the devastating effects of growing dyes on the soil, as well
> as on the economy & the workers. From the cave to Josef Albers, plus
> bibliography. (The index, BTW, has 20 entries for indigo, none for
> Indanthrene or -throne.)
>
> Judy
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