I always wash my fabric. I also "wash" the batting. I want them to pre-shrink before I sew because I don't like the wrinkly look. I have even "washed" the quilt top before quilting if I used pre-cuts such as jelly rolls. I just put them in the water, spin dry on slow, then put into the dryer with a bath towel. It takes some careful ironing to get the seams to lay flat, but I think it is worth it.