Natural Dye Workshop 5
Posted 6/26/2008 10:40am by Eugene Wyatt.
Indigo Blue, Part 1
Laura wants 15 skeins of Ember, a color that begins as another color called Sunset which comes from mixing madder, fustic & logwood gray extracts.
Laura wants 15 skeins of Ember, a color that begins as another color called Sunset which comes from mixing madder, fustic & logwood gray extracts.
Ember
Jen, Laura’s daughter-in-law, liked Ember for its subtle color variation, she wanted a sweater-coat knit from it and Laura offered to knit the coat for her; but we had only two skeins of that color in the stand; it would have to be dyed. To get Ember we must over-dye Sunset with indigo; fortunately at the farm we had 24 skeins ready to be over-dyed.
If there is a science to working with natural colors, then working with indigo is an art, if art is defined as surprise; this color requires the blessings of serendipity. The final blue is often unforseen, but usually it is a pleasing hue.
To exactly match the color would be impossible, and to come acceptably close to it would not be easy either, but I decided to try. 15 skeins is a large order, Laura didn’t blink at the price, how could I balk over my doubt.
To exactly match the color would be impossible, and to come acceptably close to it would not be easy either, but I decided to try. 15 skeins is a large order, Laura didn’t blink at the price, how could I balk over my doubt.
Source & History
A variety of plants have provided natural indigo throughout history, but most indigo is obtained from those in the genus Indigofera, which are native to the tropics. The primary commercial indigo species in Asia is Indigofera Tinctoria.
Indigo dye is obtained from processing the plant's leaves. These are soaked in water and fermented in order to convert the Glycoside Indican naturally present in the plant to the blue dye Indigotin. The precipitate from the fermented leaf solution is mixed with a base, pressed into cakes, dried, and powdered.
Natural indigo was the only source of the dye until July 1897. Within a short time, synthetic indigo almost completely superseded natural indigo; today nearly all indigo produced is synthetic. In the United States, the primary use for indigo is as a dye for blue jeans. After the Wikipedia entry on "Indigo"
My source for indigo extract is Earthues; it is sold as a powder. When working with extracts & dyes wear a paper particulate mask over your nose and mouth, latex gloves and eye protection as the situation requires.
Dyeing Procedure
In a 1 qt. jar I mix 2 ounces (56 grams) of indigo with a small amount of water making a paste, then I fill the jar with 3 full cups of water and stir it well. To the aqueous solution, in this order, I stir in 2 TBS of thiourea dioxide (also available from Earthues) and 2 TBS of lye to the solution in the jar. (Always add lye to aqueous solutions, and never the other way around, to prevent it from splashing back.)
Thiourea dioxide is a reagent that reduces the oxygen of the dye bath and lye raises the pH. Both an absence of oxygen and a basic (non acidic) dye bath (with a pH of 9-10) are required for the indigo to fix to the wool yarn being dyed in the pot.
Thiourea dioxide is a reagent that reduces the oxygen of the dye bath and lye raises the pH. Both an absence of oxygen and a basic (non acidic) dye bath (with a pH of 9-10) are required for the indigo to fix to the wool yarn being dyed in the pot.
The indigo/thiourea/lye solution is set aside in the shade for a half an hour to let the thiourea reduce the oxygen in the jar; it will turn from a blue to a dull yellow. At this time I prepare the bath by heating water to 130 F in a stainless steel pot, using about 4 gallons of water for each pound of yarn to be dyed; then I add the indigo/thiourea/lye solution to the pot and stir gently.
Until now we have been scientific and specific, but art and experience are required to get the blues you want. With a spoon, to determine how much oxygen remains in the solution, I check the color of the dye bath: to dye indigo well the solution must be a blue blue-green, not a blue (too much oxygen) and not a lime-green (too little oxygen). Upon addition of the indigo/thiourea/lye solution to the bath its color will be blue at first. One must wait about 15 minutes for the thiourea to reduce the oxygen in the pot. If the blue blue-green is not green enough then add another TBS of thiourea to the bath. If it is too green, agitate the bath to introduce oxygen.
Until now we have been scientific and specific, but art and experience are required to get the blues you want. With a spoon, to determine how much oxygen remains in the solution, I check the color of the dye bath: to dye indigo well the solution must be a blue blue-green, not a blue (too much oxygen) and not a lime-green (too little oxygen). Upon addition of the indigo/thiourea/lye solution to the bath its color will be blue at first. One must wait about 15 minutes for the thiourea to reduce the oxygen in the pot. If the blue blue-green is not green enough then add another TBS of thiourea to the bath. If it is too green, agitate the bath to introduce oxygen.
I used a pH meter when I began dyeing indigo, but it broke; now I rely on the slipperiness of my fingers after sticking them into the dye batch to tell me the pH. Basic solutions are slippery; the more basic the slipperier they are. pH 10 feels more slippery than pH 8. This knowledge is the experience, if not the art, of dyeing and your fingers can learn too.
When the bath is ready, judged by its color and its slipperiness, the yarn is immersed in the pot, and your heart pounds, “Did I do it right…bumpety, bumpety, bump…O the art…”
When the bath is ready, judged by its color and its slipperiness, the yarn is immersed in the pot, and your heart pounds, “Did I do it right…bumpety, bumpety, bump…O the art…”
To be continued...
My name is Youngil Koo who is a High school art teacher in Korea
I would like to attend natural dyeing workshop in August
Would you give me more informations about your workshop, like admission fee,
If I can stay in some place near from workshop, what do I need to bring materials,,,,etc.
My older sister who speaks and listening English perfectly will be there with me to help me
I used dyeing with mushrooms and some other materials already but I want to attend workshop
in U.S
Thanks
Youngil Koo