Blackout fabric is a type of material that is designed to block out light that passes through it. It is typically made from a heavy, tightly woven fabric that is coated with a light-blocking layer or has a special finish applied to it. Blackout fabric is often used in window treatments, such as curtains or blinds, to create a dark and private environment, particularly in bedroom or home theater settings. Most commonly it is the lining behind another fabric blocking all light from passing through the face fabric. Using a blackout fabric on windows can reduce glare on screens such as televisions or computer monitors, make bedrooms completely dark for sleeping and to improve energy efficiency by reducing the amount of heat and light that enters a room. Blackout fabric is also popular in the hospitality industry, where it is used in hotel rooms to block light from entering the room, ensuring a good night's sleep for tired travelers.