My friend Ann bought an indigo kit from ProChem, which contained "pre-reduced" indigo. I don't really know what that means, but we followed the directions, and the results were spectacular!
On the left is our prepared indigo vat. We mixed it up a few days before using it. It's about 3 gallons of stuff (water, indigo, thiox). One important thing about indigo is that it changes when it interacts with the air, so you want to introduce as little air as possible into the vat. This plastic bucket has a tight-fitting lid.
We've prepared several pieces of cloth, both cotton and silk. Most effective are pieces that have been mechanically resisted -- meaning we fold and clamp, or fold and stitch (wrapped in Tyvek). We did some of each. Here are some of the pieces before dyeing:
The pieces shown above are all white cloth, but Ann also dyed a piece of cotton she'd previously dyed with our usual fiber-reactive dyes. She used small buttons, and wrapped rubber bands around each one (detail on the right):
The bundles go in the vat. We attached a long string and clothespin to each package so we could keep track of them.
As I understand it, indigo is not a dye, but a pigment, meaning it accumulates on the outside of the fiber (as opposed to dyes, which chemically bond with the fiber). So the dyeing method involves dipping each piece for a few minutes, and then exposing it to the air for 15 minutes.
When we first take the bundles out of the vat, they don't look blue, but a fairly light green. The indigo only turns blue when exposed to the air. This is why there's the dipping and airing...
Here are some pictures of the bundles the first time they emerge from the vat.
They get progressively bluer as they are exposed to the air.
For a deeper hue, you repeat this cycle. We dipped our fabrics 3 and 4 times, and the result is amazingly intense. After the dipping and airing, we unwrapped the bundles. This is always exciting!
Here's the stitch resist, which was wrapped in Tyvek in the pre-dye picture. Above, I'm taking the stitches out, and then I unfold the layers.
You might detect the green in the photos above; the indigo hasn't fully oxidized in the parts of cloth that were inside the package. With time, it all turns blue of varying intensities.
Here's an even better illustration of the green effect. The picture above shows the bundle after I've removed the sticks, but before unwrapping. The outside of the package has been fully oxidized after its previous dippings.
As I unfold the cloth, we see all the places where the indigo has penetrated, but which haven't yet gotten exposed to the air. They'll all turn blue, but the green is a transitory treat!
We also got some surprises. Go to the next page to see what happened with two of Ann's pieces!
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