I pre shrink my batting by soaking in the washer filled with water, don't let it agitate. Spin the water out, may need to spin a second time. Dry in the dryer, fluffing often on a low setting. Be careful not to let the damp/wet batting stretch. I use 80% cotton 20% poly. If I use a 100% poly I fluf it in the dryer on air dry. Hope this helps.