Fish scale the surface, interacting only with the riblet tips, not causing any high-veloctiy flow in the valleys. Since this high velocity flow now only interacts with the riblet-tip, which is a very small surface area, the momentum transfer which causes drag is now much lower than before, thereby effectively reducing drag. Also, this reduces the cross-stream velocity fluctuations, which aids in momentum transfer too. The rough, sandpaper-like texture of shark and ray skin, coupled with its toughness, has led it to be valued as a source of rawhide leather, called shagreen. One of the many historical applications of shark shagreen was
Lampshades made from human skin years later: The charges were made once more when she was rearrested, but again were found to be groundless. Journalist Mark Jacobson claims to be in possession of this lampshade, but those claims are disputed. Ed Gein was a killer and body snatcher, active in the 1950s, who made trophies from corpses he stole from a local graveyard. When he was finally arrested, a search of the premises revealed, among other disturbing artifacts, a lampshade made out of human skin. Gein appears to have been influenced by the then-current stories about the Nazis collecting body parts in order to make