For some batik fat quarters I got at my LQS, I washed them by hand in the kitchen sink. One particular piece was washed/rinsed 21 times before it left the water clear. I was certainly glad I chose (1) to pre-wash (2) wash it in the sink where I could see the dye coming off the fabric. It was good batik, just way too much dye! I always pre-wash my material just to get the chemicals from the warehouse out of the fabric as it bothers my asthma.