See also: a "font" that only people high on drugs can read!

https://qri.org/blog/psycrypto-contest

https://www.youtube.com/watch?v=oD4nV0CMkBI

Of course, the psychedelic hidden message is reversible with some video processing techniques for everyone else to see. And calling it cryptography is a mis-use of the term. Still an interesting use of the effect.

I don't think "ghost font" will work as well as the author claims.