The term 'theatrical curtain' can be summarized as a large piece of fabric used to cover the stage during a performance. The most common type of theatrical curtain is the SCRIM, which is a lightweight, semi-transparent fabric that allows light to pass through it. It is often used to create a dreamy or ethereal atmosphere on stage. Scrims are usually made of muslin, cotton, or silk and can be painted or dyed to create different effects.