I've been experimenting with a new technique that (for lack of a better name) I've been calling "differential dyeing". I'm weaving a fabric with cellulose fiber warp and animal fiber weft, then dyeing it twice - once with fiber-reactive dyes under alkaline conditions, to dye the cellulose, and once with acid dyes + acid, to dye the animal fiber. The end result is pretty interesting, though I've only done my first set of experiments.
Here is a running horse, dyed first with yellow fiber-reactive dye (dyeing the tencel warp) and then stenciled with blue acid dye (dyeing the alpaca weft):
You can see the "differential dyeing" in the background, where the tencel dyed yellow and the alpaca dyed blue. The pattern is a 2/2 twill, producing stripes.
In this photo you can see what happens when you introduce a more complicated pattern into the weave:
You can see the diamonds give a very different effect than the twill! It's more complex, more visual interest, more "jazzed" in feel.
I wrote up a bunch more stuff about this on my blog, at http://www.tienchiu.com/2011/03/differential-dyeing-part-ii/
What I'm wondering is, is anyone else working with this technique? I doubt I'm the first to come up with this idea, and if anyone else is working with this, I'd love to get in touch.
I will post this as a project in Weavolution once I've had a little more time to "get" the fundamentals of this technique.