I've got all 23 fabric pieces (most at 6") in the washer with a color catcher and retayne. I tried doing it in the sink and there was way too much color coming out of the fabric. Going to keep an eye on it and see if it might need a second wash! I am doing Black and White strips with 2 greys.
You should have seen me scouring around for that 23rd piece! Whew! I stopped at my LQS yesterday to get 1/8th yard of all their "dark reading" B&W's and I sure didn't want to go back and get one more!