The sashing on each block edge is just 1/2 inch. If I wanted larger sashings, I would cut the batting 14" to start, cut the backing to 17",(would this be large enough?)trim the batting to 13 when quilted, and trim the backing to 16 so there would be enough backing to fold over to catch the quilt top. Hmmmm, you have put another thought in my head....may have to play around with that as well!!