richard tomlinson

Hello

This is just a quick post .... is there ANY info out there about the practice of using logwood dyes in antique Chinese rugs. I have seen some rugs advertised as 'maybe' having a logwood dye.

A few questions;

1. Is it a red dye (as a replacement for perhaps madder)?
2. Does it tipfade and if yes, to what colour?
3. Where did the logwood dye come from?
4. Was it practised in just one region or was its use widespread?
5. Is it found in rugs from other regions?
6. Is there any way of detecting that it is indeed logwood? (e.g. the color)


Any help would be great and any pics as examples even better...

Regards
Richard Tomlinson

Pierre Galafassi

Hi Richard,

According to Mark. C. Whithing «...The dyewoods are an important category, to judge from the literature. Examination of a large number of archaeological specimens has not given the writer much experience of the group, perhaps because they easily fade in light (and are, therefore, destroyed while in use) and are not resistant to degradation when buried. They are mordant dyes: brazilwood (Caesalpinia brasiliensis L.) producing red with alum and logwood (Haemotoxylon campechianum L.) producing black with iron being the most frequently encountered. The insoluble dyewoods (camwood, barwood, and the like) are larger molecules and easier to extract; they are little known in dye-analysis work....»

I have no practical experience with dyeing wool or silk with logwood nor brazilwood, but their chemical structure is coherent with Whithing’s claim of poor lightfastness and easy biodegradation.

Whether, at least, brazilwood and sappanwood were used in antique Chinese rugs or not, I can’t tell. It is not impossible though, since traditional Chinese rooms weren’t that much exposed to sunlight and lightfastness might not have been much of a concern. Safavid Persian-, Tibetan- and Chinese dyers used another (red) dye similarly limited in its lightfastness (Carthamin red extracted from Safflower).

A scientific paper by Yun Ye, L.G. Salmon & G. R. Cass (Journal of the American Institute for Conservation, Vol 39, Nr 2, Article 5), tells us that «Su Mu» (Sappan wood and its close botanical cousin Brazilwood) were indeed known as traditional Chinese red textile dyes (mordanted with alum) yielding good wet fastness.
By the way, the name Brazilwood is misleading since this botanical species was also native of India and the Malay Peninsula, thus well known in Asia, long before the discovery of Brazil.

However the authors do not list logwood as a traditional Chinese dye, probably owing to the fact that this botanical specie is native of Yucatan and the neighbouring lowlands of Mexico (See D. Cardon, Natural dyes, pages 263 and following) and may have been imported late in China, at the earliest after the second half of the eighteenth century, or, perhaps, never was.
Logwood dye was one of the most important commodities for european dyers during about a century. However, it was mainly used for black shades with iron mordant and tannin. («Tuxedo black»), thus IMHO of little use for rugs. These black shades were wet- and light-fast on wool, silk and cotton, while purple-, lavender- and blue shades obtained with logwood and other mordants (alum and tin mainly) were too fugitive.

Logwood can be detected by thin layer chromatography or HPLC, provided the analyst owns a sample of the dye, as reference.

Best regards
Pierre

Unregistered

pierre

thank you for your most informative post !!!!

regards

richard

Rich Larkin

Hi Richard,

When you asked the questions, did you have a specific rug or rugs in mind? Care to share?

Rich Larkin

Marvin Amstey

I also would like to know what specific rug you have in mind since I have a few Chinese rugs with clear fading of red dyes.
Thanks.

richard tomlinson

hi all

i did not have a specific rug in mind but i recall seeing several chinese rugs advertised as having a faded logwood dye.

*** the rug below is currently on the market so please refrain from comments as to its value***

the images below are of a chinese rug with several shades of red that have faded to a brown/camel looking colour. the rug appears to have some age and i was wondering about old chinese pieces that have faded dyes. my understanding is that a logwood dye is a natural dye (not synthetic) but appears to have the same problems that we see with many synthetic dyes.

regards
richard

Jeff Sun

This fading looks consistent with the fading on a ningxia pillar rug of mine. It is of rather recent vintage.(20-30yrs) and was previously discussed on this forum. My feeling is that the red dye was not adequately mordanted for reasons unknown.

Logwood would be an interesting explanation, if it could be verified.

richard tomlinson

hi jeff

thanks for your input. i would like to state that in no way does the seller of this rug say it is logwood. the implication that it MAY be is strictly mine.

you mention that your pillar rug is recent (20-30 years). the images posted here are of a rug much older than that.

perhaps mordanting of red dyes was / has been an issue for the chinese as it has been with other groups....??

regards
richard

Marvin Amstey

Here is an image of a very old pillar carpet, circa 1800. I have had this rug for more than 30 years. In the upper left corner is an old linear re-knotting repair. When I acquired the carpet, that repair was much less prominent. The entire red-orange ground has faded in these 30+ years so that the repair has become much more prominent.

Unregistered

hi marvin

i was wondering how, until now, you had accounted for this fading given the fact that the red could not possibly be a synthetic (if your dating is correct)?

regards
richard

richard tomlinson

hi again

i have been reading murray eiland's book 'chinese and exotic rugs' and this is what he has to say regarding logwood and brazilwood dyes in chinese rugs.

"… apparently in carpets of the precommercial period there was no intention of employing bright reds. Much of the red dyeing was done with neither of the strong reds but with varieties of dye derived form wood of the genera Caesalpinia and Haematoxylon. Most of this wood is from trees that grow in tropical forests, and some of these thrive in the tropical parts of Asia.

“Brazilwood” is the term used for the best know dye from Caesalpinia (it supplied the name for the country of Brazil, not vice versa). In the wood it is colourless, but when dissolved in boiling water, particularly with a tin mordant and various tanning materials, it is oxidized to give a variety of reds.

Hematin is the dyestuff derived from the material called “logwood” from Haematoxylon campechianum. With the proper mordants it gives a variety of red-blues that can verge towards violet, brown, and even blue-black. It is also found in a colourless form and is oxidized in boiling water.

Both brazilwood and logwood were used in Chinese rugs and they can produce similar shades that are difficult to distinguish visually. Apparently, however, brazilwood was much more commonly used, and as more is learned about the use of this interesting dye in other areas, one begins to understand the peculiar qualities of the red in Chinese rugs. First, the colors produced from brazilwood are notoriously fugitive to light but somewhat more fast to washing. " (pages 25-26)


regards
richard

Marvin Amstey

My accounting for the fading is just as Richard quoted from Eiland's book. I have no other information or authority to quote. I've had that book since its publication date.
As to the approximate dating of my rug, it is consistent with the dealer's and my interpretation and confirmed by John Edelmann when he had his auction house in NYC. Lastly, it has a strip of partially corroded brown at the top of the carpet also consistent with the generally held view that such was the case in 18th c. Chinese carpets.

Pierre Galafassi

Hi all,

Summarizing Dr. Dominique Cardon’s «Natural Dyes», pages 263-289 and 686-687, and confirming Murray Eiland’ s opinion mentioned by Richard:

Logwood (Haematoxylum campechianum L.), sappanwood (Caesalpina sappan) and brazilwood (Caesalpinia echinata) are all part of the same botanical family, the leguminosae.
They contain mixes of chemically similar but not identical homo-isoflavonoid dyes, which all are mordant dyes and share a tendency for decent wet-fastness but very poor light-fastness. The only exception seems to be the iron- or copper-mordanted logwood dye-mix.

The main dyeing component in logwood dyeing is intensely colored haematein formed by oxydation (by fermentation) of the natural substance in the heartwood of logwood called haematoxylin, a much weaker dye.
Haematein, with some help of tannin (another main component of logwood), mordanted with iron salts or mixes of iron- and copper-salts, leads to strong black shades, both as dyes (for wool, silk and cotton) and as pigments (for inks), which all are very fast to light. Actually, they even often tend to darken further with time and exposure to light. Hematein & tannin were the base of the famed Victorian «jet-black» or «tuxedo black» for textiles and of the «notary black» for inks.
Together with other mordants, especially tin-, chromium- or aluminum salts, logwood yields various subdued- to-dull violet-, parma- and rose-shades, all invariably of very poor lightfastness. As mentioned before, Logwood proper is native of America and was much later known than sappanwood (native of Asia) and brazilwood (native of Asia and America).

The main component in both sappanwood- and brazilwood dyeing operations is the strongly colored brazilein, obtained again by oxydation of the natural substance brazilin, a rather weak red dye.
When mordanted with alum or tin, brazilein (mixed with various similar minor dyes whose chemical structure was only recently elucidated), supply beautiful reds, in part brighter and more fiery than rubia reds, but very fugitive to light.
Sappanwood was traded internationally from the Middle Ages onward, later followed by brazilwood from Indonesia. Despite attempts by various authorities to stop their use due to their fugitiveness, they kept being used for centuries for all kind of red shades, mostly in mixture with light-faster but less attractive reds. Cheating is no recent invention.

Richard Tomlinson’s’ question about the type of light fading of brazilein might be answered by a twelfth century Hispano moorish silk (ibid. page 282), dyed with brazilein and a trifle (European- or Asian-) cochineal, which shows a pinkish beige background. One could therefore assume that brazilein turns beige when exposed to light (cochineal is quite lightfast on silk, and probably responsible for the pinkish part of the grey).

Owing to the facts that
1) «logwood» was often used as a generic term for dye-providing wood and not always specifically for haematoxylum campechianum,
2) Proper logwood was a very late arrival on the market, while sappanwood and brazilwood were in use since at least the tenth century in Asia and Europa,
3) Logwood supplied, next to black, only subdued and rather bluish shades, while sappanood and brazilwood gave also strong and bright reds.
4) sappanwood is documented as being the source of «korozen» a fiery red for silk in tenth century Japan,
one can suppose, Richard and Marvin, that if your Chinese rugs were dyed with this family of dyes, it was rather with sappanwood or brazilwood than with logwood.

Best regards
Pierre

Marvin Amstey

Once again, thank you, Pierre, for your educating us and your thoroughness.
The best for a happy holiday season,
Marvin

richard tomlinson

hi pierre

i echo marvin's sentiments - excellent stuff, thank you very much !

regards
richard