Covers create a complex interplay between the visible and the invisible. They attract attention and shape perception. The authors of this volume approach this phenomenon from folkloric, art historical, and media studies perspectives. They illuminate various forms and aspects of the cover as well as strategies and practices of revealing and concealing. Love boxes and mutable image media from the Middle Ages, digital media, tattoos, museum buildings, masquerade in performance art, or the con artist - all of them play with the ambivalence of the cover and its mediation of (in)visibility.