This is a heavy-duty, double-bias fiberglass tape. Two opposing layers of fibers run through this cloth "on the bias" or at 45 degrees to the run of the roll. The very best for molded chine construction. The 24-ounce is 17 ounces of biaxial cloth backed up with 7 ounces of epoxy-compatible mat. The mat keeps the edges of the tape from getting "stringy" and unruly. Rolls are 10-yards long.