Blackout curtains, also known as room-darkening curtains or thermal curtains, are a type of window treatment designed to block out light and provide privacy. These curtains are made from thick, opaque fabrics that prevent sunlight from entering a room, creating a dark and cozy environment even during the brightest parts of the day. They are particularly popular in bedrooms, home theaters, and nurseries, where light control is essential for better sleep, relaxation, and creating a suitable ambiance.

The primary purpose of blackout curtains is to eliminate or greatly reduce the amount of external light that penetrates through windows. This is achieved through the use of tightly woven or layered fabrics, often with a light-blocking lining or coating. The materials used can range from heavy polyester blends to dense cotton weaves, providing excellent light-blocking capabilities