Hide a secret message in magnetic flux!
This project uses small rare earth magnets to spell out our hidden message. The magnets are arranged in a 5 x 7 matrix for each letter and covered with a layer of plastic to hide the magnets from view. The message is only visible when you pass magnetic viewing film over the message. I used opaque plastic to hide my magnets, but you can hide a message under almost any smooth, thin surface such as a picture, poster, street sign.