I’m making a set of 4 placemats for a friend that are pieced - HST - and soon I’ll be ready to sandwich them. My question is .....what do I use for the middle layer: thin cotton batting, cotton flannel, stiff interfacing or nothing, which is what I did for some mats I had made my parents? My opinion is that too thick of a batting might make an unsteady surface for glasses and stemware (wine glasses) so I tend to think very thin batting. I plan to do some of the line quilting I did on the table runner that I posted about, if that influences your advice.