I always piece my backs. I save leftover pieces, extra blocks, etc from the front and incorporate them into the back. My backs are usually more creative...perhaps because I am so ready to finish the quilt! I never use a kit so I always have leftovers bits and pieces. It's a great way to get rid of scraps! I have a mid arm so I do my own quilting. I've never worried about seams when piecing fronts/backs. Never had a problem either.