I would think outside the box with this and make the silhouette out of something with some texture, with no backing under it to keep the softness. Use something like nubby toweling if you can find a black, or make your own chenille fabric. Instead of cutting it out of one large piece, you could add the texture in pieces so that the stitching will hold it in place and not suppress too much of the texture. If you add it after the piece is quilted and it gets messed up, you can just unstitch it and sew a new silhouette on it.