shape a fitting logo on honey products. Plate 19, Parquet, seems at first to show a stack of identical cubes, arranged so that each layer is offset with respect to the one below it, forming the illusion of an infinite, three-dimensional staircase structure. But if you look carefully at the cubes, you will notice that each corner is the center of a regular hexagon. I still remember my amazement when, as a physics student, I first noticed this six fold symmetry in an object that at first thought should only have two- and fourfold symmetries. It takes a while for the eye to recognize this, as the entire array seems to jump in and out of space, at one moment appearing as if the cubes point straight at you, only to reverse their orientation at the next. An optical illusion? A trick that the brain plays with our eyes? I let the reader decide