I like to wash most of my fabrics before I use them. I like to see what happens after washing. I've twice had flannel pill so badly I did not put it in the quilt, glad it did not happen after I finished the quilt. This was a good piece of flannel to, pd $5.00 on sale, and the cheap stuff from Walmart never did that to me. I don't like surprises, also I do want it to shrink some when I mix with cotton so than they will shrink closer to the same amount after the quilt is finished.