I would not wash any of it.....I made a bunch of rag quilts using denim on the back and flannel on the front and didn't have a problem at all...both fabrics were new.....and denim doesn't shrink at the same rate flannel does and all my quilts are still holding up....I double check sometimes to make sure...that's when I can...Q4K you can't double check or other charity quilts but those I have given to family and my own have held together fine!