You've got a lovely quilt/bedrunner. If you are thinking that you need more inches on the back to account for what will be taken up in quilting and to leave yourself some leeway, cut the back into four equal parts and put strips of the top fabric--you could even piece them piano style--between the sections. If you use 4 inch strips, you will have lots of room and you will have added a striking design element to the back. Good luck and happy sewing. froggyintexas