Bald caps are a specialty in and of themselves, and for a long time demonstrating that you could apply one was a requirement for membership into any of the makeup guilds. From start to finish, the application of a bald cap, including makeup, can realistically be expected to take from 2 to 3 hours.
Bald caps can be made generically and fit just about anyone, or they can be completely custom made for a specific head. Generic caps are usually made from either latex or vinyl, whereas custom jobs can be foam latex or even silicone. The late Richard Snell, who showed me how to apply a bald cap, was the best and could put a bald cap on someone with hair down to her waist and make it look as though he’d shaved her head. I don’t have a photo of that, unfortunately, but I do have one taken by one of my former students at IMATS, the International Makeup Artist Trade Show, in Pasadena, California, in 2004. It shows Richard applying one of the custom silicone caps he was known for. He was an amazing guy.