Hidden messages with magnets

Picture this: To the naked eye, a design is hidden. But once you run magnetic field viewer film over the magnet, you’ll see a hidden message. If you have some magnets and an 80w laser handy, you can etch your own secret messages that only those with magnetic field viewer paper can read.

How It Works

According to Hackaday, a magnetic experiment has been successful in using an 80w Quelab hackerspace laser and a 2” x 1” magnet in achieving this hidden message scenario. If you want to try this at home, we’d suggest a 1/4 x 1/8" disc magnet to ensure that the magnets would be strong enough through the "thick plastic board.”  

Initially, it wasn’t clear if the laser cutter would be able to penetrate the strong neodymium magnet, but it was found that when the magnet was heated above the Curie temperature (180F-250F), the magnetic properties of the material started to break down. When this occurred, the laser had enough force to etch the almost visible design onto the magnet. Once they scanned the magnet with magnetic field viewer film, the etched pattern was completely visible. You can check out our video here to see a magnetic field viewer film in action.

Hide Your Own Messages

If you don’t have a laser cutter laying around, you can still hide messages using magnets! Instead of etching designs into a magnet, you can use disc magnets hidden in thick wooden boards to hide messages. Use a drill to carve out slots to hide 1/4"x 1/8” neodymium disc magnets. After you spell out your message in magnets, seal it away by securing an additional thick plastic board over the wooden one. Once the plastic is covering the design, it will only be viewable when you use the magnetic field viewer film! You can read a detailed tutorial on our page here.

Find More Apex Magnets Crafts

These two magnet experiments take the phrase “more than meets the eye” to another level. With a few tools, you can create amazing magnets with hidden secrets that you can share with your closest friends and family members. For more magnetic crafts, check out our magnets for crafts blog here.