the thing with the ZF4 is the narrowness and many cases have a high ridge on front,, so that it's a challenge to type the "side letters" on the keyboard (A, Q, etc). Nevertheless I don't have the stones to go naked; some of the many cases I have/have tried and like: Supcase Unicorn Beetle, Ghostek gray with leather (beautiful! but a little tough to type on), Samsung's cases, etc etc