If it's just for decorative purposes, then batting like Warm & Natural will do. If you plan to put hot things on it, use Thermore or something like it - the heat doesn't go through to whatever it's on. I used to use 2 layers of batting for potholders but now I use Thermore (Pellon makes a similar product) so that I can quilt it more easily. Most of the time, the table runners I give as gifts don't seem to be used for hot things. :-)