“…We produce and test two packing configurations for each packing density, one in which all fibers are aligned in a square grid (aligned) and another in which fibers in an adjacent row are shifted laterally by a /2 (staggered), as shown in Figure c. Fiber size and spacing, scriptl and a , determine the intrinsic porosity of the array . The ratio of empty area to that consumed by fibers on any single row of the array is given by A R = a scriptl + a an intrinsic porosity which we call the “aspect ratio” of the array.…”