I have never had any appliqué that I satin stitched come off but I haven't used it on children's quilt that are laundered often. I have used my buttonhole stitch with wonderunder on a couple. They have not come off but I notice with washing that the edges look kind of frayed. They may need a repair in the future. I would just trace the piece that came off and appliqué by hand or raw edge appliqué/quilt in a new piece.