In the fashion world there are scarves, and then there is the scarf. Queen Elizabeth II wore one for her postage-stamp portrait. Jackie Kennedy kept the Nantucket rain off her hair with hers. And when Grace Kelly broke her arm in 1956, she memorably knotted her scarf into a sling. With some squares priced over $2000, this is one of the costliest pieces of silk one can buy—a fact that does not keep the things from floating off the shelf at a rate of two per minute. If you can’t guess what this accessory is by now, you’ll probably never own one. After all, Hermès—France’s most storied luxury brand—doesn’t advertise much, and it hardly needs to advertise its scarves at all.