A Thread Is Passed Through An Envelope Containing A Card. The Card Remains Untouched.

A little preparation is required before the performance of this trick, but the effort gives a fine result.
A card may be chosen at random, and placed inside a small envelope. A thread is now passed through both sides of the envelope, with the card trapped inside. The thread is now forcibly ripped from the envelope, leaving it destroyed. And yet the card contained in the envelope is free from all damage.