It may depend on the batting used. I have a sit down machine and tried using fabric on top and poly on the bottom. Stitch quality was awful. Ended up putting ugly fabric on bottom so it would quilt well. I am making (WIP) a mat for a 3 yr old. It will be double sided, with train tracks on one side and a roadway on the other. I’ll include a selection of matchbox vehicles with the gift. It was the only solution I could come up with.