I use flat bed sheets all the time. You can get them in single pkgs. at Walmart but the ones I like best are single sheets from IKEA. Wash & dry them befor using to remove the finish they put on them. You can't order them from IKEA online. Have to get them at a store. For me it's a 45 min trip you many times I have used the ones from Walmart. I use the leftover scraps in scrap quilts.