Poly batting is the problem, I used the cheap cotton batt from Joanns, then either use a double layer of muslin or Joanns sells the metalic material in either quilted or smooth (the price on this has skyrocketed). Most important of all is to stretch it tight and staple. You can make the top removable similar to iorning boards with a draw string but you really need to get the underlayers stapled firm.