Just before I want to Woolfest I tutored a dye workshop. During the course of the week-end we did some indigo dyeing. I love wool, so naturally I had lots of hanks of yarn, including some lovely Blue-faced leicester gimp.
I had some in hanks and some in centre-pull ball, so in a quiet moment I managed to "dunk" them in the indigo vat.
The first ones to go in where the hanks, which I tightly hanked, giving them a really good twist, until I couldn't twist any more. I then gave them a good wetting out, followed by a good squeeze and placed them one at a time in my vat. I pushed them carefully under the surface then allowed the hank to bob back to the surface.
The image on the left shows, clearly, the coppery coloured film of a vat that is in good order.
Carefully removing the hank, catching any drips in a jug, I allowed the hank to oxydise briefly, before unwinding and hanging on the line to fully oxydise. The image on the right shows the hank as I unwound it before hanging on the line.
Here is the hank hanging on the line to dry after washing and rinsing, with a final rinse with a small amount of vinegar in the water.