I recently made 2 table cloths one with flannel only on the back and the other with warm and white between. The one with the flannel which was washed 2 times in hot water still shrunk and for me it just doesn't look very nice . The one with the warm and white is holding up quite well. Also I think with the batting it gives more stability for glasses and things. With only the flannel back you can feel more of the piecing seams. Is that confusing? Just my opinion.
Good Luck
Suzy