Spies Rejoice, A New Technique Turns Water Into Invisible Ink
In an age before computers became our master form of communicating , invisible ink was a favorite style to pass information without draw in unwanted attention . It may have always been more common in detective stories than real life sentence , but it was easy enough to make at rest home . The idea may be less important in popular culture as information technology develop , but fluorescent ink that can only be show under ultraviolet light are in increase demand for text file security ....