Magician's wax is a staple of both stage and close-up magicians. It is a special, highly refined species of wax, with a number of special properties that make it particularly suited for use in prestidigitation.
The most common use of magician's wax is the making of magician's candles. These candles are light (making them easier to levitate) but still strong enough to be hollowed out for the storage of a magical prop (say a specially trained "collapsible" dove).
Before fashions changed, magician's wax was also often used to wax magicians' mustaches.