Material is 1 1/2 Inch by 3/4 ". Forward edge of two cross pieces measure 19 1/2" and 14 3/4" . They are cut at an angle to fit the rear taper. Outside dimensions of the seat itself are 10 1/4" fore and aft, 11 3/4" side to side. Mine is from 1963 so has the grooved and woven cane seating.