The design specifications I set for this pad were numerous. I wanted:
(1) An easily replaced common notepad.
(2) An instant access impression.
(3) Eliminate the necessity of ripping the page from the notepad before drawing on it.
(4) Reset it instantly, even in front of people.
(5) A design innovation so cool that it would delight Mentalists when they saw it (creator’s pride!).

I think the Butterfly meets all the above criteria. I really, really like this thing.

Keep in mind that my devices are meant to be used regularly for optimal performance, and if they sit unused for long periods, the wax can sometimes harden causing the magic slate to not work. The wax must be soft and somewhat sticky for the device to function properly. Sometimes warming up the board, and using the slate a few times will restore the slate to working order. I've had people contact me saying they ordered a Hornet or Butterfly a year or two years ago, and this is the first time they've tried to use it, and it doesn't work. I'm not surprised. If you leave your car sitting unused in the driveway for a year or two in the driveway and try to start it, you'll probably get the same result.

The Effect

-- of course, is one of Information Replication. A person writes down a piece of information: a word, name or drawing, and you reveal it. The Butterfly is the Modus Operandi; your performing skill is the critical element to selling the effect.