The curtain that closes off almost the entire stage is called the___________

The curtain that closes off almost the entire stage is referred to as the "Act curtain." This term describes the curtain that typically separates the audience from the acting area and is used to signify the beginning and end of a scene or act in a performance. The act curtain is usually a large and prominent curtain that can be raised or lowered, allowing for dramatic entrances and exits and providing a visual cue to the audience about transitions in the performance.

The grand teaser, while it does play a significant role in heightening the proscenium arch and helping to mask the top of the stage from the audience, does not serve as a curtain that closes off the entire stage. The grand drape is a specific type of act curtain that is often luxurious and serves as the primary curtain but is more accurately associated with the front of the stage rather than closing off the entire stage's acting area at once. The cyc, or cyclorama, is a background curtain that is typically used to create a seamless backdrop for lighting effects and does not function in the same way as an act curtain.