Sometime in the past I saw a performer present the M-box effect. He inserted his hands through the front and top simultaneously creating a beautiful illusion of transparency. Does anyone know who originated this move?
When S.S. Adams put out their cardboard M-Box, it was common for magic store demonstrators to insert their thumbs in the top and front doors, and wiggle them. That was the first time I saw it done, back in the 60's or whenever that box first appeared on the market.