The silk fibers of the brown recluse spider feature a unique morphology: they are 50 nm, thin, flat ribbons. H. C. Schniepp and co-workers test the mechanical properties of individual ribbons in their work on page 7028 and find that they are extraordinarily stiff and feature a nanostructured surface. These filaments-fiber and thin film at the same time-are so extremely thin that they easily wrinkle, fold, and stick to themselves as they wrap around the spiky exoskeleton of an ant.