Prada presented its Fall/Winter 2018-2019 menswear collection on Sunday, in a new warehouse show space on Viale Ortles near the Fondazione Prada. The Milan-based house invited four talented guest designers to create one-off pieces for the show, from the house’s signature black nylon. Enter Ronan & Erwan Bouroullec, Konstantin Grcic, Herzog & de Meuron and Rem Koolhaas.