11/8.5 = 22/17 = 44/34 = 1.29 17/11 = 34/22 = 1.55 These have the property that they alternate aspect ratios every size, so you have to go up two sizes (4x ar

11/8.5 = 22/17 = 44/34 = 1.29 17/11 = 34/22 = 1.55 These have the property that they alternate aspect ratios every size, so you have to go up two sizes (4x area) to get back to the original aspect ratio.