The materials come in different forms such as foam, film, foil, chopped fiber, glass wool, polymer, fibrous mats, and in a board or block. The board is further made into sheets and strips, fibers are pressed into a mat by braiding, weaving, knitting, or pressing it into the mat using adhesive. Almost all insulation are rated fireproof; but, most of them only resist fire and are not effective beyond a certain temperature.