Originally Posted by citruscountyquilter

I piece my backings all the time. In fact I've never made a quilt that I didn't have a seam in the back. The back has always been quite different from the front however. I wouldn't try to match the front to the back. You do want your seams on the back to be as straight as possible however. When sandwiching your quilt if you mark the batting and the backing with the center edge and the center middle of each piece it helps to match things up. I use a frixon pen or you can run some basting stitches as reference points.
To match up the center which you can't see through the layers try taping two straws to your table in the shape of a cross to mark your center point. You'll bee able to feel the lump through the fabric layers depending on how you are basting layer the the quilt together. You'll be able to see the center markings on the edges. Since I glue baste I put my batting down first and then lay the backing over that and then fold the backing back to put the glue on half the batting and then do the other half. In any event the straws keep me on track to keep the centers together.