This beautiful 1898 Commercial Visible Typewriter types from a type wheel, that is easy to remove, allowing for a quick change of font. To make an impression, a spring loaded hammer behind the carriage swings forward, striking the paper and ribbon against the type wheel.
Weekly Innovation: Turn A 3-D Printer Into A Tattoo Machine
Working with his fellow design students, Piotr Widelka and Johan Da Silveira, Emm took a MakerBot Replicator 3-D printer and reconfigured it to "make the machine more incarnate," as he describes to NPR. "An image passes very quickly ... I wished to give them more time." So the students hacked a printer to write an image on human skin.