I have been researching the history of the boudoir cap, and I am fascinated by these adorable little accessories that were essential to the proper ladies' nighttime and early morning wardrobe. I have found countless examples of these fancy little caps, and four of my favorites are pictured below....the ribbon work, the delicate laces, the silks and satin.....I am amazed just thinking of the time that was devoted to making one of these precious adornments!
For lots more examples visit my Pinterest board "Boudoir Caps". https://www.pinterest.com/simplepleasuressleepwear
Analysis of a Twentieth Century Boudoir Cap http://www.ryerson.ca/content/dam/fashionresearchThe boudoir cap was evolving and by the twentieth century, though still deeply tied to notions of femininity, the allegiance to strict rules of decency seemed to loosen. Though no caps were still worn they no longer completely concealed the hair (Webster 170).
https://vintagefashionguild.org/lingerie-guide/cap-boudoir/Boudoircaps were worn in the 19th and early20th Centuries to protect the coiffure while undergoing the arduous process of dressing or to cover undressed hair. As long hair was bobbed short in the late Teens and 1920s, this was unnecessary due to the shorter hair lengths.