A hair bonnet for sleeping, also known as a sleep cap, is a close-fitting cap worn over the hair to protect it from tangles, breakage, and loss while sleeping. Made from a variety of materials such as silk, satin, or jersey, these bonnets create a smooth surface that allows hair to glide against it without causing friction or damage.
Hair bonnets have been used for centuries to protect and preserve hair, particularly among people with curly or textured hair. They provide numerous benefits, including reducing frizz and breakage, retaining moisture, and extending the life of hairstyles. One notable historical development was the invention of the "Dandy" bonnet in the 18th century, a style that became popular among fashionable men and women for its decorative and functional qualities.