Advance Preparation and Setup

Make a copy of the two Blackline Masters for each student. If possible, buy inexpensive “cans,” which can be aimed and which have a slot to hold a filter (get these at a theatrical supply company). Set up the three colored lights so the beams all overlap on the screen.
Be sure all sockets have the wiring safely covered. If you use ceramic sockets with screw terminals underneath, screw the sockets down to a board so these terminals will be inaccessible.