Using prequilted fabric is a great idea! My quilt group is currently making these, but from scratch. So far I've made one top and most of a second one (started with the left-over half square triangles cut from the first one!). Now, as it turns out, my MIL may be needing to use a wheelchair occasionally so am going to make her a special one. I'm thinking of adding a pocket to it because she frequently needs to use tissues so she can keep a packet of them handy.