I have started using a light weight iron on fusible Pelion set right side of appliqué to rough side of Pelion. I draw my shape on the Pelion, then stitch around complete shape. Slit the Pelion near the center and turn right side out. You will have the iron on side facing the back side of your fabric. Flatten and smooth the edges, then press in place. Stitch down around the edges. Flip to the back side and carefully trim away the backing fabric leaving at least 1/4” to 1/3 inch around the edges and press again. Now you can add any other pieces without adding bulk or stiffness.