Thursday, January 26, 2012

A&S 50: 47- Indigo dye silk and cotton - modern method

Fibers before dying

Picking up where I left off with my last attempt at dying with indigo (working with wool and linen), I decided my next attempt should focus on cotton and silk fibers.  The cotton will eventually be used as the pattern weft for a Perugia towel and the small amount of silk will probably be used for some tablet weaving experimentation.

As has already been discussed, indigo is a close chemical relative of woad, one of the earliest known dyestuffs used in Europe.  It is unique in the universe of dyestuffs in that it requires no mordant to produce bright, colorfast shades of clear blue.  This makes the dye process relatively simple, in that the fibers to be dyed require no pre-treatment, however development of the dye vat can be a very complicated process as all oxygen must be removed from the water in order for the indigo to process and adhere to the fibers.

Having attempted to use a chemical-free method of developing the vat and failed miserably, this time around I opted to use the simpler, modern method relying on color run remover.  While not a period process, this poses several distinct advantages; first the smell is limited to that given off by the indigo alone, and second the dying entire process can completed in a few hours rather than a few days, thus further limiting the unpleasant smells.  I can finish my dying and air the house out while my husband is as work, and he will be none the wiser to the day’s noxious activities!  (Did I mention the indigo stinks?)

Stinky, stinky indigo paste
The process:


  •   A total of 8 oz of fibers (I dyed 2 oz of cotton, .5 oz of silk, and approximately 4 oz of handspun alpaca and still had usable dye in the vat)
  •   10 grams indigo, ground as finely as possible (my indigo is in chunk form so I ground it myself in a morter)
  • 1 tsp washing soda
  •    1 oz color run remover
  •   Small jar
  •   A crock pot that will never ever have food in it again
  •   Spoon

"bloom" of scum after vat has processed

I set fibers to soak in warm water.  While fibers were soaking, I ground my indigo and added it to the washing soda in a small jar.  I mixed this with a small amount of boiling water to make a paste and stirred to dissolve all the particles.  I then added water to my crock pot sufficient to cover half my fibers at a time and the color run remover and set it to “low” to warm up.  Windows were opened and the kitchen fan was turned on to start airing thing out as the indigo stink was already getting bad.

After 30 minutes, I added the indigo to the crockpot carefully, trying not to introduce any air bubbles in the process.  There was grit in the bottom of the indigo jar, so I spooned a bit of the dye vat water into jar to get this out and added it to pot.  I gave it all a gentle stir, and let the whole thing sit for 45 minutes to develop.

A thick scum of indigo had formed on top of my vat so it was difficult to tell if the dye has turned the greeny-yellow I was looking for, but with some gentle poking it looked all right.  This bloom of scum is apparently normal and cannot be avoided.  Not sure how the dye book authors get their nice clear vats for the pictures, but there you go.  The cotton and silk went in first and set for 20 minutes.  They came out beautifully, with a deep rich blue on the cotton and a vibrant blue on the silk.  I had a few white spots where I had tied my skeins too tightly, but I repositioned the knots and dip dyed those sections for about 10 minutes and the skeins are more even now.
Finished yarns, alpaca, cotton and silk

The alpaca went in for 20 minutes after the cotton and silk were finished and came out a grayish blue.  This is I think because it started out a natural tan color rather than white.  Again, the take up was a little sparse where I had tied the skeins too tightly.

  • I need to tie my skeins more loosely to get more even dye take up
  • You can stir the vat!  Just really really carefully
  •  Indigo stinks, did I mention that already?


Dean, Jenny.  Wild Color.  Watson-Guptill Publications, 1999.

Bingham, Gayle.  Woad Dying.  Medieval Textiles issue 29. Sept. 2001. ( Last visited Nov. 18, 2010

Kolander, Cheryl.  Dying with Indigo – Natural Fermentation Vat.  ( Last visited Nov. 18, 2010.

Priest-Dorman, Carolyn.  Colors, Dyestuffs, and Mordants of the Viking Age: An Introduction
 ( Last visited Nov. 18, 2010.

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