Autumn is the season not only of new looks on the catwalk but also of new looks on the small and silver screens as the television companies and Hollywood unveil their latest programmes and Oscar hopefuls. For what happens on TV and in cinemas can be at least as influential as what is shown on the runway. And as screen stylists strive to create believable characters, perhaps their most important craft or skill is hairstyling – and wigs.

Consider the example of Downton Abbey. Each series requires 30 or so wigs, each wig needing to be washed and restyled after every three days of filming. For the forthcoming new series Downton’s hair designer Magi Vaughan immersed herself in the early 1920s. “I looked at paintings, watched old films and got books from the 1920s with hair techniques such as the Marcel Wave,” she says. Literature also helped. “I read Bright Young People: The Rise and Fall of a Generation 1918-1940 , by DJ Taylor and We Danced all Night by Martin Pugh. You get a lot from the text; for example, in the 1920s women were competitive about the sharpness of their bob.”

Or consider the example of Carey Mulligan, or, rather, consider the example of Carey Mulligan’s hair. Last year the sharp 1920s bob she modelled in The Great Gatsby was everywhere. This year “Carey is filming movies back to back so needs to wear wigs or it would wreck her hair and waste time on set,” says Michael Kriston, a hair designer who worked with Mulligan on the forthcoming Coen brothers’ film Inside Llewyn Davis.