That being the case, Timtex is very helpful for the stiffness of the post card. Pentax works as well but not as stiff. It is in the interfacing section of the quilt store or Joanns. It is cut by the yard. Now if you don't want a real stiff post card, you can get the heavy wonder under and fuse it onto your fabirc getting a little bit of stiffness but will be pliable. Then you hand stitch on your index card for mailing or heavy card stock. Works.