Tetko is a synthetic cloth used as a lining fabric. The author has used Tetko with a variety of adhesives including wax resin, Beva, and Bernie Rabin Hot Melt. He feels it is easier to handle than fiberglass as it doesn't shear, cause splinters, doesn't need to be prestretched, and has dimensional stability. One layer is not stiff enough to keep cupping or serious tears in place. Pecap is the trade name of this polyester which is defined as a manufactured fiber in which the fiber forming substance is a long chain synthetic polymer composed of at least 85% by weight of an ester of a dihydric alcohol and terephthalic acid.