A density of a nanofiber sheet can be changed using an edged surface, and in particular an arcuate edged surface. As described herein, a nanofiber sheet is drawn over (and in contact with) an arcuate edged surface. Depending on whether the arcuate surface facing a direction opposite the direction in which the nanofiber sheet is being drawn is convex or concave determines whether the nanofiber sheet density is increased relative to the as-drawn sheet or decreased relative to the as-drawn sheet.