I've used wool battings for many quilts, it's my favorite batting. Dream wool and Hobbs wool are the two I use. I've made quilts with prewashed fabrics, not prewashed fabrics and some prewashed some not in the same quilt. Every one has turned out great. Those wool battings do not shrink like cotton batting does. It is lightweight, lofty and wonderful to work with. Each time I launder one of those quilts it comes out of the dryer soft, lofty, huggable, wonderful.