This is a video from Youtuber and relaxing talker Applied Science discussing and demonstrating how to apply holograms to chocolate with no printing ink or plastic or anything on the chocolates. How does he do it? Basically by pouring liquid chocolate onto an existing hologram so the chocolate hardens with the same ultra-fine diffraction pattern that created the hologram on the original. Simple! “You don’t understand this at all, do you?” I drunkenly emailed Applied Science last night and told him to stop trying to pass off his sorcery as science. *stumbles out of bed knocking beer cans off nightstand* I know what you are!
Keep going for the long, almost too informative video. This man has some gadgets!
Source: Geekologie – Valuable Info: How To Apply Holograms To Chocolate