Numberground by Mickael Chatelain - Trick
On the back of a playing card, you use a magic marker to draw the card your spectator chose just a moment ago. Show him what you drew, and then determine this does not even remotely look like the chosen card. Don't panic. When you shake the card, ever so carefully, the drawing changes very visually, until it corresponds 100% to the chosen card. A magical change! You hold the card merely with your fingertips, and you can show it on both sides! An effect not unlike "Wiregram", which will surely find its way in your card routines. Very easy to learn and to perform.
Comes complete with gimmick card and instruction sheet.