Since the newer Tron movie came out a few years ago, there have been tons of costume ideas involving EL panels and tapes. EL, or electroluminescent, products are very interesting. They are sheets of material that light up when electricity is applied. The light that is emitted is extremely smooth, lacking the hot-spots you would get if you tried to light an area with LEDs for a similar effect.
This video caught me completely by surprise, though. I have never seen this product called Elastolite, which is an extremely flexible EL panel. So flexible, in fact, that it may be adhered to someone's skin and covered with makeup to effectively create a glowing tattoo.
The final result in this video by the folks at Sparkfun is incredible. The Elastolite is flexible enough to conform to the natural curves of the body, though you'll still have to work out where to hide your battery pack and inverter. If you're interested in giving this a try, Sparkfun has collected all the necessary components into a convenient wishlist for you. We'd love to see what you do with it!
— Caleb Kraft, Chief Community Editor, EE Times