I only use Quilter's Dream and it says NOT to prewash. Frankly I wouldn't wash any other batting either. I can't remember what cotton batt I used before I started with Quilter's Dream only but would never have washed it. I did throw some in the dryer on occasion if they were really wrinkled but you could also lightly press the wrinkles out if needed. I spray baste and so it is easy not to have to worry about kinks in batting as you just smooth it out as you sandwich your quilt.