I used a really heavyweight Pelmet Vilene, (UK product). So I had backing fabric, Vilene, Batting, top fabric. It makes a firm placement, but I was still able to machine quilt through the whole sandwich without any problems. I have also used this same Vilen to make fabric bowls, so I guess it would be similar to Timtex (? I think that's what is recommended in the books) that is available in the USA.