When I use Steam-a-Seam or similar product for applique projects, I generally stitch around the item using either a button hole stitch or a small straight stitch. It helps cut down on fraying and adds a decorative element. It would work the same for a label, I think. Another idea that might work for you is to attach your label to the back of the quilt before quilting and then it will quilt it right to the quilt. I like this idea but usually don't have the label ready in time. Hope this helps.