Maniac Quilter love your placemat. Our church just finished making placemats for our local Meals on Wheels. They had a ton of 7 inch squares-a lot not quite square. I went to our local glass shop and had them cut me an acrylic 12 x 18 shape. Used that to cut the backing and front, no batting, just sewn tog with a 5 inch opening to turn. Some I made using strips like yours and some I used orphan blocks and 3 inch strips for the sides. The reason we did not use lining, we made 580 of them so we had some time and money constraints.