If you want to edge stitch the appliqué by machine, it is going to show on the back. If you don't want that then you will have to hand stitch the appliqué to the front. If it is a simple shape, I suggest you do the turn inside out appliqué with a used dryer sheet or light interfacing. You put the dryer sheet against the right side of the appliqué shape. Using a small stitch length you stitch around the appliqué shape. Clip or use pinking shears to cut 1/4 inch around the appliqué edge. Cut a small slit in the dryer sheet to turn the appliqué right side out and press until perfect. It is now ready to hand appliqué to the quilt surface.