For the quilt mentioned in the project that started this thread, I would keep my eye open for a large scale print with some color, but with a white background and some black in it. I often love to make the backs, because I can get as creative as I want. I'll follow a pattern for the front, but the back can be much simpler, and only have a passing acquaintance with the front. They usually are very simple, and in some cases I like them just as much as the front. I keep my eyes open for sale fabric that I think would make good backing, and snap it up. A lot of my quilts will have at least some of the colors that I go to all the time, so a fabric that contains those will always be useful for me.