Red Or Black?

Effect: From a pack of cards spread face down on a table, you are able to tell which are red cards and which are black.
Secret: First separate the reds from the blacks. Bend all the red cards upwards. Bend all the black cards downwards. Mix the cards together. Spread all the cards face down on your table. Throw them down haphazardly and then invite a spectator to mix them up even more, so it is obvious they are not in any special order. Ask people to point to different cards and you can tell them if they are red or black by the way they bend.