This is the way I do all my "fold backing to the front" quilts. I have been doing this as long as I have been quilting, about 5 years. And before that I did a lot of home dec sewing, so to me this is not a new way of mitering. What is really nice on the napkins is to use a wing needle and a fancy stitch to stitch down the hem. When I do this on my quilts I use the blanket stitch to make a nice secure hem.