I made a jacket and quilted the fabric with cross hatching. I quilted it and then cut the pattern out. Your pattern pieces will be more accurate if you do it this way and you wont have to worry. What I did do instead of quilting the 4 whole yards was lay the pieces down in sections like the both pieces for the arm and allowed a generous amount around it and then cut that large piece, quilt it and then laid the pattern back down and cut them out accurately. You may not need to do this since it's a purse but since I was making a jacket it made it more manageable to do it in sections making sure it was large enough for the peices but trying not to waste too much fabric. I have a little bit of frugalness in me. I hope this helps. Good luck with your project. By the way, doing it in sections was the idea of my teacher/friend, I didn't come up with it but it sure made it easier.