size	1	2	3
8″ x 10″	34-36	27-29	34.5-36.5
11″ x 14″	36-38	29-31	36.5-38.5
13″ x 19″	38-40	31-33	38.5-40.5
16″ x 20″	40-42	33-36	40.5-43.5
20″ x 36″	42-45	36-40	43.5-47.5
24″ x 36″	45-48	40-44	47.5-51.5