Plexi penetration

A pencil pierces a Plexiglas panel to which playing cards are clamped. The cards are pierced, but the panel remains intact!

The perfect penetration of matter!

And this is what your presentation could look like:

"Shall I tell you the secret of these cards?" you ask, looking around . "Their center is indestructible!"
To prove this, you take out a pencil and immediately reveal a small plastic frame. This frame encloses a Plexiglas panel, onto which you now clamp a card, both front and back.
"Now comes the proof!" You pierce the top card with a pencil, then the Plexiglas disc and the bottom card. You extensively display the results of your destruction.
Finally, you pull the pencil out of the frame and remove the two cards. "Oh, that's strange..." you murmur, as the result of your skill becomes apparent: Both cards have a hole in the middle, but the Plexiglas panel in the frame remains completely intact.
Everything can be examined immediately, your viewers will discover nothing and will be left with a puzzle.
“Miracles happen again and again...” is your final comment on this presentation.