My favorite is the poly that has stickem on both sides. If you are making a simpler quilt you can piece it right on to the batting as you go. I've done this with both straight edged pieces and curves. When you are done you wash it and the stickem is gone and you are left with a soft quilt. It is a huge time-saver. Also, I have grandchildren who can't have polyester against their skin, but they have no problem with any poly-filled quilts.