This cube reveals its inside once it is solved. Just hide your secret message and a fragile glass vial with a poisonous gas which will be released, should someone decide to break the cube out of frustration instead of solving it (Please, please don't poison anybody, I'm just kidding ;-)).
Step 1: What you need
• at least 25 two millimeter cubes (22 for the Rubik's cube and three to make a rig, but you should get a few more, in case you mess up)
• Oskar’s Treasure Chest (from Mefferts)
• Wood stain
• Clear finish
• Hot glue gun
• Strong two component glue
• Phillips screwdriver
• Dremel (114 High Speed Cutter, a Sanding Drum and a 3 mm drill)
• Optional: laser cutter, but the graphics are easy enough, so you can just paint them on.