Curtains that can close off part of the stage from the audience's view are known as what?

Travelers are curtains designed to move across the stage, allowing them to open or close off specific areas from the audience's view. They operate on a track system, which enables them to travel laterally, either pulling together to close or separating to reveal what's behind them. This functionality is crucial during a performance, as it allows for scene changes, transitions, and the creation of different playing spaces without completely revealing or exposing the entire stage.

In contrast, scrims are typically used for special effects—they appear opaque when lit from the front but can become transparent when backlit, rather than functioning as traditional concealment curtains. A cyc, or cyclorama, is a large backdrop used to project colors and light effects, often creating an illusion of depth in the background. Lastly, a backdrop is primarily for scenic purposes, providing a static visual element behind the action on stage but does not have the capability to open or close like travelers do. This delineation of function helps clarify why travelers are the correct answer for the given question.