While I doubt the super serious stiff in this DIY video is actually a super spy, he does have the DIY know-how necessary to hack apart an inkjet printer and make it into an invisible ink-spitting espionage machine. Enjoy! [MAKE]
A new book reveals that a member of MI6, the British spy agency, discovered during WWI that semen makes excellent invisible ink and often deployed it in the field. The name of the man who discovered this? Mansfield Cumming.