Hi David,
Let me first thank my Counsel
Rich Larkin, who has indeed perfectly summarized my point. And Joel who
has taken the trouble to search for the slides in the archives.
I do not think that you and I,
David, disagree as much as you might think.
There is indeed no
doubt, as you state, that some of the
early synthetic dyes, in
particular the so-called «aniline dyes» (triphenyl-methan dyes ) are easy
to identify even on pictures, because of their absolutely lousy
light-fastness, far worse than any natural dye traditionally used for
rugs.
It is also true that other
early synthetic dyes,
mainly some red and magenta so-called «acid" dyes, are notorious for their
poor wet fastness (bleed), worse again than traditional natural red rug
dyes (Correctly applied madder, lac and cochineal reds do not run under
the wet conditions to which rugs are supposed to be exposed, including
cold washing).
However, these lousy synthetic dyes appeared on the
market during the second half of the nineteenth century (ca.1860 onwards)
and were gradually replaced by better dyes even before the end of that
century. First, by better «acid» dyes, then from 1920 onwards by so-called
«migrating 1/1 chrome complex-» dyes, which rapidly achieved over 90% of
the market for rug dyes. Both the wet-fastness and the light-fastness of
this later generation of carpet dyes are good, at least as good as the
best natural dyes and mostly superior.These 1/1 chrome dyes are not
significantly brighter than the usual natural carpet dyes and shrieking
shades cannot be produced with them even by mistake.
Several
carpet-producing regions actually banned by law, with severe penalties,
the most disastrous
early synthetical dyes.
Now, sure, a
handful of these lousy «anilin» ancestors are still produced (for other
uses) and one can still buy them, not only on markets in Pakistan or
India, but also in Europe or USA. I still fondly remember an epochal joke
using 100 g of the «anilin dye» called Victoria Blue when I was a
(mischevous») kid. (This was long ago of course, but still well into the
twentieth century).
And it is true too that modern «acid dyes» for
polyamide (suitable for wool) do feature, in part, very bright shades.
However, their lightfastness is now comparable and mostly better than the
one of natural dyes (thus no fade) and their wet fastness is superior to
the ancestor’s (hardly any risk of bleed).
These modern «acid» dyes are
not supposed to be used for carpet wool, but they probably are
nevertheless used, for various possible reasons like greed (they are
cheaper than 1/1 Cr complex), the weaver’s taste for shrieking shades,
ignorance etc..
However, even with such
modern bright "acid"
dyes, well chosen and used in «trichomy» by a competent dyer (I assure
you, for having worked with them during 35 years, that most are
competent), one can match perfectly
all shades obtained with
natural dyes. In that case, no experienced eye, only HPLC or TLC will give
up the fraud. As many experienced rug purchasers and dealers know, the
little ahem...forgery is even sometimes perfected by the weaver by an
addition of cheap
spent fibers of natural dyes to the dye-bath.
Some fibers remain attached to the wool and are supposed to prove a dyeing
with natural dyes.
I can only quote Rich: ... «when the proper
technical analysis is done, even among persons with an experienced eye,
there are more than a few surprises». One of the causes of «surprises», as
often mentioned by Steve in these pages, is that one takes as a fact that
when a dye fades or bleeds on a rug it is, without any possible doubt, a
synthetic dye. Unfortunately this «fact» is wrong:
- Some (few) recipes
with natural dyes can bleed and some others can fade (just give a look at
some «polonaise» Safavid rugs).
- The synthetic dyes most used since
the early twentieth century by industrial dye-houses and serious artisans
neither bleed nor fade.
I suppose, David, than after my (much to
wordy) post we still can debate on what «
few synthetic colors» is
supposed to mean in percentage.
Best regards
Pierre