CNC Foam Cutters are capable of cutting out some pretty cool shapes that would ... kit that came with the 4 axis stepper motor control board and 4 NEMA 23 stepper motors. GMFC software is used ...

If you don't want to use a potato you could cut your design out of foamboard like this and then stick it onto another piece of foam board to make your printing plate. OK. Now for the messy bit.