Ask for a scrap of Tyvek at a construction site, or buy it. We don't use a footprint, and when it's damp I sometimes wish we had. Before washing (it's really noisy and cumbersome if you don't) sit down in front of the television for an hour or so and crumble it up every way you can, wringing it out frequently as if it was wet. Then wash it. It will come out soft, covered in creases and nearly completely quiet when you roll around on it. In my view, it's much better than those you purchase, both for its durability and its cost.