Another thought...if you want to stabilize the quilt for FMQ, but do not want the design to include stitch in the ditch, you can machine baste it with water soluble thread. Once you are done with the quilt, the basting will come out in the wash.
Do not be deterred by the cost...a little goes a long way! I've basted several quilts with a small spool of the thread. It's a quick and easy way to securely hold the quilt together. I also spray baste, but this assures me that it will not shift when quilting. Especially important on larger quilts for me because my quilts get handled a lot while I'm working on them. I don't have a "sewing room" and have to move my stuff out of the dining room constantly.
http://www.redrockthreads.com/misc-t...ble-thread.asp