The way the tool works is that you first take some aluminum foil and make a ‘U shaped’ form using the special tool to do so and make small incisions on pre-determined positions. Next thing you do is put the foil over a special blank that already has the profile of your target lock. The clever thing about this tool is that the ‘U shaped foil tube’ is wrapped around some sort of needle, and the foil can not be pushed in when entering the lock! Once the key is inserted, the needle is taken out from the back of the tool, and the pins are now resting on the foil. Because of the cuts in the foil, each pin will stand on it’s own ‘island’ of foil, and when it is pushed in will not disturb the neighboring pin!

This technique will open most locks and you can buy a kit for around $58,- or a simpler model for $21,-

via Advanced foil impressioning « Blackbag, Barry’s weblog.