I generally cut 2 1/2" but it depends on the thickness of the batting. I have used 2 1/4 " with thin batting like Quilter's Dream Request. Often I make a sample first. I sew on top, hand stitch back. I do not enter mine in shows so it doesn't bother me that much if there is more on the back than front. If making stitching line on front wider than 1/4", you would need to take into account if you will be cutting off any points, e.g. With pieced border. I made one wider binding and did not like it immediately after doing it and still don't.