I’m in the basement of the Royal Opera House, Covent Garden looking at costume treasures. Here are the thirty-six snowflake tutus for The Sleeping Beauty, double-layered and decorated with elaborate detailing. There’s the sweeping blue cloak worn by the mysterious magician Drosselmeyer in The Nutcracker, with its trick pockets for his magic tricks. I wander past rails of soldiers’ tunics, dresses for garland girls and even a wolf outfit, where the tail neatly passes through a hole in the tights, allowing the dancer full body movement. It’s a wonderful insight into the backstage life of The Royal Ballet.

The Royal Opera House is home to the largest collection of theatre costumes in the UK. Each year it lays on over fifty productions on its main stage alone. No wonder head of costume Fay Fullerton presides over a one hundred strong team (plus around sixty freelancers), with a department that extends over four floors of the building. With nearly everything – from props to dresses to wigs – made on site, the process involves long hours spent handcrafting each bespoke garment.

Costumes are made to last (some are still being used by the Royal Ballet forty years later). For each revival they are brought out of storage and fitted to the new cast in the workshops at the Opera House. Tailors work from the ‘costume bible’, that details original designs and subsequent revivals, to make sure that costumes stay accurate to their original design. Faded colours are re-dyed, worn darning is repaired. Working on five to six opera and ballet productions at a time, carrying out around 6,000 fittings per season, it pays to plan ahead. They buy in a small number of costumes for some contemporary productions: but where possible, if a show is not in use any more costumes are recycled for other shows.