I always preshrink my Warm and Natural Batting. I put it in the washer with hot water and let it soak till its completely wet. Keep pushing it down into the water because it will float. DO NOT LET IT AGITATE!!! Then I spin it out and put it in the dryer. I've never had a problem with it shredding. It softens it so that I can hand quilt it easier. It prefer that if its going to shrink, that it shrinks before i put it in a quilt. I also preshrink my fabrics, too.