I made a 36" square -- the top is the silver ironing board material, the center has 1 layer of insulbrite and two layers of warm and natural, the back is a fabric and I sewed ties on one side so I could roll it up and take to class. For several years (until I had room for an ironing board) I just used some cotton that I had. When I moved it went to a friend who didn't have room for an ironing board and I bought myself the gridded pressing board.