Thanks, everyone
Thanks for the replies! I have some good (heavy) muslin that was given to me and I have washed it. I'm old enough to remember that you always wash everything you sew with! And, still have the habit. I thought about making "reversible" table runners but the designs would be so different that I don't think the quilting would work for both sides.
Anyway, I still have to finish the tops so will continue to think on the backing - want to have everything done by mid-May. Thanks again.