I prewash Warm and Natural batting. I put it in the washer in hot water and leave the lid on the washer open so it doesn't agitate. I let it soak until it is really wet. Then I turn the washer on spin cycle and get the water out. Then I put it in the dryer. I hand quilt and the batting is softer and easier to qullt that way....to me any way. I do not let the washer agitate because i was told it would ruin the batting. Once the quilt is finished, then by all means agitate when washing.