Here you will find ready-made backdrops ready for hanging on e.g. stages or in theaters, often also called theater curtain and stage curtain in molton fabric.
A backdrop is often used by bands and other performers who hang the backdrop behind the stage. Often you'll also see branding using the backdrop with a logo, band name and other "gimmicks"

Most stage curtains and backdrops are typically wood-impregnated, as they often need to be placed near powerful lamps and other types of stage lights that give off a lot of heat. Many of the ready-made backdrops also come with either eyelets for hanging. Or Velcro so they can be stapled together to create a backdrop of just the right size.

Several companies also have molton backdrops for hire if you only need the stage curtain for one night.