I found that heavy duty poster putty holds a big quilt to my wall. Non toxic, no markings and cheap. I put a circle of putty about every three inches along the back of the quilt and press to wall. Size of circle depends on the weight of the quilt. Also I use in along the sides and bottom of the quilt, the quilt hangs perfectly flat against the wall. I don't leave any one quilt up for more then a few months so I don't know how long term like a few years the wall would do to the quilt backing. If it was going to be a semi permanent wall hanging I would line the back with white cotton fabric over the backing.