English: Casio F-91W watch with customised light-on-dark inverted/inverse/negative display showing the time. (Achieved by removing original polarising film and replacing it with one oriented at 90 degrees offset. While the result looks fine here, this photo was taken at a near-optimal angle and- for whatever reason- viewing angle is now very shallow (i.e. vastly inferior to original display) with legibility dropping off quickly at any other orientation.)