Prada’s Re-Nylon backpack (center) reimagines the company’s 1980s classic in material made from discarded fishing nets and textile refuse. Clockwise from top left: An example of backpack functionality; an expedition camping tent; Naomi Campbell walking Prada’s fall 1994 show in a nylon dress; nylon fishing nets.When Miuccia Prada introduced her now-famous nylon backpack in 1984, the gesture was, if not confrontational, then certainly contrarian.…