I quilt on my Janome 6600 and will use what I have or can find for backing. I've used regular quilting cottons, wide backing, flannel, and sheets. I've never had any issues with any of them and always wash all of them before using. Using a sheet as a backing can be a great thing if you are doing a kids themed quilt....kids love the prints and very easy to get an extra sheet to make matching curtains.