Monday, March 30, 2009

Using up natural dye liquor - Spring Cleaning

I had some pots of natural dye liquor that I've had outside in the ice and snow from last fall. One was of coreopsis blossoms. Another jar was of spent cochineal bugs that had been save and allowed to ferment on the kitchen counter. Another of spent madder roots, again left on the kitchen counter and fermented.

The madder had no colour left and was tossed. The cochineal bugs had lots of colour left and laid down a madder-like red on wool/mohair in the first dip with 200 grams of yarn. The coreopsis laid down a golden yellow, although a bit saddened compared to the yellow of fresh blossoms in summer.

I still have a pot of logwood to try. I hate to waste the colour even if its pale. It can always be overdyed.

Saturday, March 21, 2009

Woad in North America

Woad was brought to North America by the early European settlers. Seeds were imported from Britain for household use. In the 1830's, woad was listed in the seed catalogues in Ontario, as the plant was common in household gardens.Commercial dyers also used couched woad imported from Europe, and the working of the woad vat was considered the accomplishment of a Master Dyer. Indian Indigo was also used but as it was more costly, it was not as common for household use.

A first year woad plant. Although the woad plant contains indigo precursors at every stage of development, the first year rosette has the highest indigo precursor level, and is the part of the plant most commonly used for commercial production.

Woad is being grown today for oil seed production, a wood preservative, artist pigments and artisan dyeing. Very little commercial production of woad-indigo is being done today, however two enterprises are attempting a revival of woad production in UK and EU.
The European woad growers recognized 2 distinct types of Isatis tinctoria. One, which the French called "Pastel," has smooth leaves (microscopic hairs can be seen), high indigo content, and was valuable for cattle fodder. A second type, which was referred to as "Bastard woad" was contientiously rogued out of the pastel patch.It had coarse, hairy leaves, a low dye content and was unpalatable to livestock. (Chaptal, John Antony. (1839) Chemystry Applied to Agriculture.- available in google books)
It is the "Bastard woad" that came to the USA and threatens to overrun Western range land. It began in a 1900 contamination of Alfalfa Seed in Calilfornia, which got away.
This is the woad being used today by natural dyers in North America. Its indigo yield is low and the hairy leaves contaminate the dye bath with soil and other impurities which inhibit the extraction of indigo from the leaves.

Friday, March 20, 2009

The website is updated

It been weeks of work. But now its finished. Well is a work of art every really finished?

I've updated the whole website, adding pages about the indigo precursors in woad, my innovative woad extraction method, thank yous to everyone who sent me woad seeds, dye samples, books, articles, and encouragement.

My science board is almost completed. OK, I'm on my third revision since last Friday. I keep thinking of new things I should have added.

So I hope you enjoy it and learn more about this facinating natural dye plant. If you have any questions or comments let me know.

Sarah, The student ;^)

Sunday, March 15, 2009

Woad Indigo -- a science fair project phase 3

The final stages of the student's science fair project are in process. The paper is written -- over 40 pages about woad -- its history, chemistry, biology, art and economics. The statistical analysis is done. The board was finished at midnight on Thursday night in time for the first round of science fairs.

The biggest enouragement is that the indigo yield from her woad doubled this year over last year. And it was the rainiest and coldest summer we've seen, so this is a positive finding.

She saved seed in our Canadian zone 3 range land climate, at 2700ft. elevation with summer frosts. The saved woad seed out performed the seed from 2007 and out performed the mean yields of current scientific studies -- done on prime agricultural land in Europe and UK. Wow!

Plus her own saved woad seed is rich in indigo precursors through out the growing season, unlike the purchased seed which looses most of its precursors in the early Fall, after frost.

She's getting an average of 4 to 6 grams of indigo per kg. of woad leaves using her innovative extraction method. Last year she averaged 2 gram of indigo per kg. of leaves -- the same as the European studies. According to the Maiwa documentary, "Indigo", the tropical indigo averages 5 grams of indigo per kg. of leaves, using a fermentation extraction method.

The usual method of indigo extraction from woad follows the method described by
Beijerinck in 1900, where hot water is poured over woad leaves and they are allowed to steep for several hours before being removed from the extraction vat. This method is inefficient and results in a loss of most of the indigo precursors from the extraction, since isatan A and isatan B -- the most abundant precursors in woad -- are unstable and require specialized extraction conditions. Woad has an undeserved reputation as a poor source of indigo dye pigment. By improving the extraction methods and using a seed selected for high indigo precursor content, the yields of blue pigment from woad can rival tropical indigo.

The student's method optimizes the indigo yield by taking advantage of the precursors and obtains up to 8 grams per kg. of leaves in some extractions -- averaging 4 grams per kg. of leaves over 50 extractions.

The student took first place in the High School Science Fair on Friday and is on her way to the regional science fair in April. Visit to find out more.

Woad dyed tapestry in mohair and wool with a cotton warp. Designed, dyed and woven by the student. All colours came from woad.

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