I too wonder about this. I did one for my son twenty years ago and never put a back on it. Didn't even think about it really. Now, I hear that people finish the back of the quilt but I am not sure how they do it without disrupting the stitching on front. Hope we can get some answers!
Jacquie

Hi - I also made baby quilts and table runner's and left the backing as is with the stitches showing . I just recently discover to use a All-purpose wovent fusible interfacing to cover the stitch backings. You can purchase it by yardage from Jo-Ann or Wal-mart store. You apply it with a hot iron. I now finish all my backings this way. It even holds up after washing. On my table runner's I usually hand sew a blanket stitch all around which gives a nice effect. On the baby quilt like the one showing, I run my sewing machine and sew close to the edge of the fabric. The product is call...'Pellon SF 101 Shape-Flex. Hope I was able to help you.
Aw