These window coverings are designed to soften and diffuse the intensity of sunlight entering a room. They do not completely block light, but rather reduce glare and harshness while maintaining a degree of natural illumination. For example, a room facing direct sunlight can become more comfortable and usable throughout the day with these coverings in place.
The benefits of this type of window treatment include enhanced privacy, reduced fading of furniture and flooring due to ultraviolet light exposure, and a more pleasant ambient lighting environment. Historically, variations of these coverings have been used for centuries to manage light and temperature within buildings, evolving from simple fabric screens to more sophisticated woven materials.