The Ink Ribbon Cartridge is an ammunition item in Problem Sleuth. It is used to load the Smith Corona Blotspitter. The ribbon is obtained from the Semi-Demimonde Goddess (for whom it was serving as a hair ribbon, in a case of innocuous doubling), and then the Blotspitter was used to forge an unpleasant note to DMK. Then, using the combination of the unpleasant note, the Blotspitter and the Ribbon itself, the wielder can use Pax Probliscum against a target.