Back Stage. A Classic Stage Favorite for years!
The effect is simple, a Jumbo card vanishes & reappears.So you explain to the audience you'll teach this old magic trick.
Drop the Jumbo card between the two boards on the tray. Reverse the tray so that everybody can SEE that the card is resting in the ribbon loops under the tray.
Explain this is the way magicians are fooled by magicians.
Show the trick again, only this time the card actually disappears!
Of course, since you're a REAL magician, you also make the card reappear!
A very nice outfit for the stage performer!