This effect has quite a history, I first came across it as part of a kids HOCUS POCUS magic set (I was 6 years old) made in jumbo cards, before that it was marketed by Harry Stanley's Unique Magic Company, but BEST of all, it was used by Dai Vernon to FOOL magicians during his first UK tour. He was performing what was supposed to be a pure sleight of hand routine from his book, the magicians were blown away with how clean it looked, and that's because he did THIS gaffed, self working routine instead. Gotta love Dai!

I have added the color changing picture backs. Pictures because psychologically the mind fills in the rest... right?