Blackout Curtains
Blockout curtains are a popular curtain choice for bedrooms these days because they block out the majority of the sunlight and keep the room dark.
Blockout curtains must be made with specific materials that can block out light in order to perform this function, which primarily includes heavier fabrics with a tight weave.
There is always some debate about how much light blockout curtains eliminate. The answer to this question necessitates a discussion of two other curtain types with similar characteristics, namely room darkening curtains and light filtering curtains.
In theory, blockout curtains should block out all incoming light. If you use room darkening curtains, they will block out 95-99 percent of the incoming light. Anything less than 95% falls into the category of light filtering curtains.