The composition of cues occurs in two phases. The writing phase called a paper tech is when the designer sits down with the director and stage manager to decide when each change will take place in the script and what it will look like. Each cue is assigned a number and marked in the script. After the lighting is completely installed, the designer moves to what is the most exciting and creative phase, the actual composition. Lighting is controlled by electronic devices called dimmers .
Dimmers vary the voltage delivered to each light, making it brighter, darker, on, or off.
The dimmers in turn are controlled by a computer console located in the back of the auditorium in a control room with a clear view of the stage sometimes called the light booth . When the designer sits down at the console it is much like a music composer at a piano keyboard. As each cue is completed it is recorded in the computer's memory for later playback. The lighting designer's last responsibility is to be present during technical rehearsals to ensure the proper implementation and integrity of the design and to make changes as required. Lighting designers typically come on board near the end of a project.