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 show this was the case, but later more sophisticated testing proved it was cow skin. In 2012, a human-skin lamp appeared in the "I Am Anne Frank" episode of "". Lampshades made from human skin There are two notable allegations of lampshades made from human skin. After World War II it was alleged that Nazis had made lampshades from murdered concentration camp inmates. In the 1950s, murderer Ed Gein, possibly influenced by the stories about the Nazis, made a lampshade from the skin of one of his victims. The display of the flayed skin of defeated enemies has a long