Cards Appear From An Empty Box

This is a favourite, not only of mine, but of many young magicians I've come to know. A great number of magicians want to learn of a card trick with a difference. I believe this one ticks all the boxes.
A card box is opened out to show that it's completely empty.
It is now folded back into the shape of a pack of cards.
The magician makes a magic motion, and immediately pours a full deck of cards from the empty box. The deck, being completely normal, can now be used for traditional applications.