Indigo dyeing workshop, part II: The dye bath

As I wrote in my last posting, over Thanksgiving weekend, I had the chance to take a wonderful shibori indigo dyeing workshop with Akemi Nakano Cohn, and in this entry, I thought I'd say more about working with the dye bath. 

I had never done any serious fabric dyeing before, and on the first day, the dye bath seemed very alien and forbidding.  When Akemi showed us how to make the dye stock solution and dye bath, I wrote down instructions in minute detail--how to make a paste with the indigo powder, how to transfer it to a Mason jar with a rubber spatula, how to mix in the lye solution, and then the thiourea solution, how to stir up the stock solution, and so forth.  There were a lot of prohibitions to keep track of: don't ever add water to lye (always the reverse, or you will regret the energy release from the chemical reaction as the water hits the lye all at once), don't mix too vigorously, or you will oxidate your stock solution and dye bath, don't wring out your fabric over the dye bath (do it under the surface of the bath), don't let the dye bath get too cold, don't splash or make lots of turbulence in the dye bath--basically, don't do anything that will add oxygen.  Also, don't forget to thoroughly wet your fabric before dyeing it.

On the one hand, there was something comfortably familiar with the setting, since I was a chemistry major once upon a time and logged plenty of hours in lab.  From that standpoint, there was nothing new about the necessity of keeping a particular solution in a reduced state.  But I also hadn't been at a lab bench in over 25 years!

By the second day, however, I felt like an old pro.  Granted, I didn't make the dye bath myself, but when I arrived, it had a beautiful yellow-green sheen, and I could tell immediately that we had particularly good bath to work with.  At a certain point in the afternoon, I could also see that the dye bath was pretty much exhausted, and I helped to stir (not too vigorously!) after Akemi added more dye stock (don't forget to wait 30 min. or so before the revived bath is ready!).

Here are two of my favorite pieces from the second day:

Both are dyed Kona PFD.  For the workshop, we were supplied with a lighter weight organic cotton, but I also bought some Kona, since it's the weight I prefer for quilts, and I wanted to see how it would do in the indigo bath.  It dyed beautifully, and I was really pleased.

The first piece is nui (stitched) shibori.  After the first day of the workshop (and after Thanksgiving dinner), I did eighteen rows of hand-stitching.  It took about two hours altogether, plus another fifteen minutes to pull all of the stitches tight.  I dipped it four times in the dye bath (dipping means putting something in for about 15 minutes, and then taking it out for 20 minutes or so to oxygenate before putting it in the bath again for another dip).  Had there been time, I would have put it in the bath for another two rounds, but even so, I'm pleased with the depth of color.

The second piece is itajime shibori, which involves folding and clamping.  I just pleated the fabric lengthwise, and then pleated the resulting long strip again, down to the right size to clamp between two rectangular pieces of wood.  The wood acts as a resist, which leaves most of the piece with just the barest tint of blue, in between the dark areas that are at the edges of the clamped fabric.  Again, I dipped four times, which made for a strong and beautiful contrast.

Maybe it's hubris, but I do feel confident about continuing my indigo dyeing experiments on my own, and I am already imagining a dye shop in the backyard this summer.