Fargo 45000 YMCKO ribbons consist of yellow (Y), magenta (M) and cyan (C) panels for printing a full spectrum of colors by combining the colors using varying degrees of heat. The K panel is a black resin panel, typically used for printing text and barcodes and the O panel is a thin, clear protective overlay that is applied to the entire surface of your cards. Fargo 45000 ribbons are specially back-coated to extend printhead life.