Welcome to the board. I've never purchased moda brand backing, but often wide backings are a slightly lower thread count than quilting cottons and have a different hand. Having said that, there's no reason why you can't use it for piecing. I do it all the time so the front has some matching patches with the backing. I'm a pre washer and have noticed that backing tends to shrink more than regular quilting cottons. To pre wash or not is a hot topic and a personal preference.