| Pierre Galafassi | May 1st, 2013 10:30 AM |
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Originally Posted by Marvin Amstey (Post
14093)
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Attention, Pierre: have you considered a retirement job to provide such a service? |
Dye testing
Greetings. I have a wonderful old textile with wonderful color and
technique. A couple of the colors have "issues," minor dye transfer to
adjacent fibers. I'd like to have two of the colors tested as to whether
they are natural or synthetic. Does anyone know where this testing can be
done? Thanks. Mark |
Hi Mark How old is 'old'? If you think it might predate synthetics, why not post some pics and see what others think about age? If the general consensus is 'really old', then testing may be irrelevant. Regards Richard Tomlinson |
'morning Mark, I tried about a year ago to locate a service and could not find one. There was a listing on a web page somewhere in the west, but they never responded. I think that there are a lot of us who would like to find a dye testing service. Attention, Pierre: have you considered a retirement job to provide such a service? |
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Greetings Ya'll
The item in question is a tentband. They seem to be the most
enigmatic of all textiles, judging from the literature. We can't even
attribute a specific band to a specific tribe with any accuracy, let alone
date the darn things. I think Peter Hoffmeister saw pictures of my band
[thank you Frederik!] and Peter thought "circa 1880." However, others have
observed Eagle group II characteristics [very fine cotton/wool plied
weft], and that it could be much older. The band is very wide, at 18".
Yes, that's right, 18 inches. Wow. The yellow dye has some very slight
transfer to adjacent fiber, and only on the back of the piece. To me the
color is "natural," and I have done considerable natural dying. But, it
would sure be cool to find out for sure! Thanks
guys! |
Tentband
Hi again: Here is a picture of the piece I'm talking about. You'll
get some idea of the scope of this textile. Thank you Steve, for the
assist!  |
Not to doubt the dating or possible origin, I have been under the
impression from reading years ago that bands that wide are rather late
editions - certainly after 1875. I once had an 18 inch band with one color
clearly synthetic, but most of it was fine. If someone can disabuse me of
that notion, please do. |
Hi Marvin I've read the same thing, but I have no idea what the evidence behind it is. I'd love to believe it's true; my one tent band is 10 or 11 inches wide. Regards Steve Price |
Thanks
Greetings, Yes that's the hypothesis. Richard Isaacson told me that's
anecdotal, and suggested that pieces be evaluated on a case-by-case basis.
This one is likely not the oldest textile in my humble collection, true,
but it might be the coolest!  |
Mark, How are you going to display it? My one complete band - also of that width and noted above - was kept rolled. No place to put it and finally sold it for that reason (not the funny color). I still retain 3 very old fragments. |
Hi Mark, "I'd like to have two of the colors tested as to whether they are natural or synthetic." If you have access to some of the first issues of Hali and if you feel confident to handle potentially hazardous chemicals, it can be done by yourself. If need be I can find out the exact reference for you. Regards, Horst |
Banding together!
Hi Marvin and Horst, Mr. Price has already sent me a thorough methodology published by Paul Mushak, in Oriental Rug Review, April 1986. It doesn't seem too daunting, and makes sense. I see that some of the chemicals [ammonia] are readily and cheaply available. And as for hazardous chemicals, I just sprayed boxelder bugs in our neighborhood, and whatever kills them can't be very good for me! I think that I will "have a go" at testing the one troublesome dye, the yellow. I have my preconceived notion about it though! Beware the Heisenberg Principle! As for displaying, that can be a problem. We only display a few textiles at any given time. My wife seems to think "less is more!" Thanks for the ideas! Mark |
Hi Mark I wonder if there is anyone at a local university that could test? I work at a large university and have always been tempted to head down to the science and biology faculties and inquire. Plenty of weird stuff going on there! Never know.... Regards Richard Tomlinson |
To Dye For
Richard, It is probably a huge and daunting undertaking to build the database necessary for just cataloging the structure and components of all the dyes one may encounter. Then you need to build a database of how to test for them individually and in combinations. Then a cross-reference, if it could be reliable, on when each was introduced. Add in all the effects of different mordants, changes in dyes due to washing, age, smoke and contaminants and you have a career-long project just to be able to get started testing a single fabric. On the other hand, once you have this established you could easily charge $25 to test one dye in a fabric.  And you still have the problem of having to test multiple samples to be sure that a single knot or two in a whole rug may be synthetic and all the rest are not. Not to mention the technique of using old wool to make "new" copies. I realize that this is a rather cup-half-empty perspective on the topic, and I am not an expert chemist to really know how complex and time-consuming the process of establishing the basic database would be. Maybe if Steve Price had started building one instead of founding Turkotek, we could be partway there by now! There is also the old saying, divide and conquer. If we got enough chemists and laboratories together, similar to using multiple computers to solve complex analyses, the job may go quicker.  Patrick Weiler |
Hi all, I just realized I had the refernce on my computer: Helmut Schweppe in HALI II Vol 1, p. 24-27: How to distinguish whether a carpet has been dyed with natural or synthetic dyes. I have gone by those instructions myself in the past. Regards, Horst |
Patrick, its the 21st century! When I was researching places for
testing, the one I found, and which never responded, was charging $250 per
color; that was in the early 70's. I did prevail upon Mark Whiting to test
two colors in an old (I thought) Turkmen only to find out one of the reds
was a mixture of madder and Poinceau 2R, therefore, not very old. I
haven't had the opportunity to do any testing since. However, it is not
inexpensive. |
Hi all, The modern analytic method (HPLC with Diode-array detectors) is, of course, way too sophisticated and expensive for any "cottage dyestuff-analyst". But the old and reasonably precise TLC (thin layer chromatography) technique is neither very costly nor difficult to use. However, the cottage analyst should limit his ambitions, for the reasons perfectly explained by Patrick : Creating an extensive date-base of dyes, natural and synthetic, is a huge task since hundreds of old- and recent synthetic dyes have been used for dyeing of rug wool over the past 150 years. Besides, samples of most of them will not be easy or even impossible to source. My suggestion would therefore be to focus only on the 15-20 most important sources of natural colorants traditionally used on rugs. These dried plants and insects can be bought easily on the Net and since only a grams of each dye will be necessary to create the data bank for a TLC operation, it will also be quite cheap. Ready-to-use TLC plates (preferably with polyamide layer), the minimal required glassware and the dozen of standard solvents, (both for the dye extraction from the wool and for the chromatography itself), can be bought from labware sites on the Net. I would advise to operate in a well ventilated place, (a garage with open door for example). With this rustic tool one would have a pretty good chance to identify most of the natural dyes present on one’s rug. Of course there would still be the remote possibility that the rug would contain a rare natural dye, of which one has no reference sample. Forget about identifying synthetic dyes though. Who knows, this modest operation could be the start of an Apple-sized mega-company:thumbsup: Below, please find the most importants natural plant- and insect- sources and the main natural dyes which each of them contains. Main natural red dyes  main natural yellow dyes  Best regards Pierre |
Hi Pierre Excellent post !!! regards richard tomlinson PS Caveat : you might get arrested for running a meth lab  |
...and for people with unlimited resources: Quote:
Chuck Wagner |
I know what I know but I don't know what I don't
know
Pierre. You have almost convinced me to start a dye testing lab on the back patio. It would solve two problems. One, I find out if my rugs are naturally dyed and two, I can irritate my annoying neighbor. :battle: :thumbsup: You indicate it may not be too complicated to determine if your rug contains naturally-dyed substances. How, though, do you distinguish if a piece of wool contains a natural dye - proved by your test - but does not also have a synthetic dye mixed with it that is not in your database? The test would be positive for the natural dye, but it would not tell you that there is also another component and whether or not it is synthetic. My collection acquisition strategy is to buy only the cheapest possible scraps of crap I can find.  That way, I am assured that finding synthetic dyes does not reduce the value my collection.  Patrick Weiler PS: I have, knowingly, purchased pieces with likely synthetic dyes. They are acknowledged to be "of an age" when pieces of their type were known to have been woven and most of which contain synthetic dyes. This is like many collections of Transitional-phase Navajo rugs which often contain synthetic dyes. Let me tell you, some of those ain't cheap. :money: |
Right, Patrick, The minimalist approach I suggested has indeed a little problem. If a dye can't be identified it is: - either a synthetic dye (one of hundreds) - or a natural dye of which you don't own any reference sample yet in your data bank. However, with the plants and insects listed above, after reading of a few books on TLC of natural dyes (the best by far being Helmut Sweppes' (*)), and with a little experimenting (which will be much fun), you should be able to prove to deadly envious but hapless friends/collectors that the pearls in your collection are full of precious natural dyes, and even perhaps to differentiate between a wool dyed with Rubia tinctoria by cold "fermentation" dyeing (described by Manfred in Salon 134) as opposed to a mere conventional hot dyeing. Please tell me before you go with the new company to the stock market, I already missed the opportunity with another (Californian) garage company (*) But Schweppe's is very difficult to find except in some university libraries, I had a copy in my company office for decades, but since its mysterious disappearance, I am looking for a new one without success. |
Hi Pierre, Have a look at this website: http://cool.conservation-us.org/byform/mailing-lists/texcons/2007/07/msg00005.html It says it has the downloadable copies of "The 3 Schweppe Dye Books" Regards, Filiberto |
Idem for this one: http://www.si.edu/mci/english/learn_more/publications/articles.html |
Just to get you started, These references available on the net will be helpful, I hope. IDENTIFICATION OF DYES ON OLD TEXTILES Helmut Schweppe JAIC 1979, Volume 19, Number 1, Article 3 (pp. 14 to 23) Practical information for the identification of dyes on historic textile materials Helmut Schweppe Smithsonian institution 1988 Enjoy Pierre |
Speedy Filiberto was the quickest. :thumbsup: Yes, these 3 texts are summarizing Schweppe's maximus opus. His book however is putting the Bible to shame (as far as weight) and is beautifully illustrated. Pierre |