The FatJab is a handheld printer that allows artists to print patterns and stories on any surface in the physical space. You simply hold it on your fist, point it against a surface, select a pattern with the thumb joystick and spray away.
It deliberately doesn't contain any sensing technology. The idea is to let the artist gain full control over the interface and distort the printed data as it's sprayed onto a surface to create a more personal rendering of a digital artwork.
It's still a very experimental interface. FatJab.v3 is up and running, but it has many usability issues that need to be resolved. There are also technical glitches like paint viscosity, pressure consistency and the purging of the valves that make it hard to make any interesting piece at all right now. Experimentation with v3 was extremely insightful and FatJab.v4 will be on its way.
If you think you've got the skills to try it, drop me a line.