THE EFFECT: You display a coin and place it in a fold of the material of your trousers. A spectator is allowed to feel the coin to make sure it's still there. Yet, under these seemingly impossible conditions, the coin vanishes completely.
THE SECRET: Place a duplicate coin you intend to vanish in your right trouser pocket.
Show the other coin and place it in a fold in the material of your trousers (next to the duplicate). Secretly remove the first coin into your palm and hide it.
Let the spectator feel the duplicate (they don't know it's actually in your pocket) While they are feeling the coin get rid of the one in your hand either in a jacket pocket or back pocket. Unravel the material and show the coin has vanished!