I have Many Times! I use Hobbs Wool or Dream Wool battings, most of my quilts contain prewashed And Not prewashed fabrics And, I always launder my finished quilts. In my world the final step to each quilt is laundering the finished project. They have always turned out beautifully! I am a Huge fan of wool batting -- and, it doesn't seem to shrink as much as cotton but adds soft, fluffy loft to the finished quilt. I launder on normal settings, warm water and toss into dryer again on normal settings. When the quilt comes out of the dryer you just want to Hug it! They are so wonderful!