Effect: A solid plastic glass in a frame is given for examination. Nothing unusual can be detected. A playing card or business card is placed on each side of the frame underneath the thin strip, so that the center of the glass is covered on both sides.
The performer now pierces both cards and the glass with a borrowed pencil. This can be followed by a silk handkerchief, a ribbon, or slender knife. The cards are then removed by the performer and to everyone’s amazement, the glass is in perfect condition and the frame can again be given for examination.