Current back panels of Lucky Charms® cereal present a puzzle printed with this coating. To solve the puzzle kids must expose the box to sunlight or hold it under a UV light. Answers appear on the carton within seven seconds. In the photo shown here the exposed answers are on the carton on the left. "It's something to entice the kids" says Barry Wegener marketing communications manager at General Mills. The Lucky Charms carton marks one of the first uses of Waldorf's (St. Paul MN) Chamelacolor(TM) Graphic Enhancement System. "It's a cross between an ink and a coating" says a Waldorf spokesperson. "We've only been able to do it in a screen printing process to date but now we've formulated it for all of our printing processes." The proprietary coating is applied in-line as the sixth color in a web-fed offset process on a 22-pt recycled clay-coated newsback. Two of Lucky Charms' three sizes feature Chamelacolors. General Mills declined to comment on further use of Chamelacolors in cereal cartons.