Because writers, as I’ve observed before, are intellectual packrats who gather up odd bits of information just in case they may need one of them someday:  The scholarly hairdresser who figured out how to do the Vestal Virgins’ seven-braid hairdo also takes on 18th-19th century papillote curls — the “curling-papers” we read about in period fiction.

When I googled on “papillote curls” to retrieve the link, I also found links to blogs where other recreationists have gone on to try the process themselves, which is how I learned that the process works best on hair that hasn’t been washed for a day or so — “every day” hair-washing being a mostly 20th-century innovation.  And in the “everything is connected to everything else” department, I liked the hairdresser’s comment that this particular style and curling method didn’t become popular until technology had advanced enough for paper to become relatively cheap.