If a film is a "period" or historical piece, like THE PATRIOT or A KNIGHT'S TALE, a great deal of research goes into the re-creation of the costumes to ensure authenticity.

The costume designer's staff consists of the wardrobe supervisor, wardrobe assistants and tailors. Stars usually have their own costumers as well as the occasional special need, such as dealing with allergies to certain fabrics or needing an extra-heavy coat on cold winter days. All of these factors are considered when the costume designer formulates the wardrobe budget, which is finalized with the producers before filming begins.

Once the budget is approved, the wardrobe team begins sewing specific costumes, fits the principal actors, oversees the necessary tailoring, and purchases or rents clothing from retail stores, costume rental houses, or studio wardrobe departments. Once filming begins, wardrobe assistants stand-by on the set to dress the actors and to organize, repair and clean their wardrobe.

Sony Pictures Entertainment (SPE) maintains its own wardrobe department which houses close to one million pieces, from feather boas to leopard print coats. The department stores the complete wardrobe from SPE's films and television shows until the air or release date in case costumes are needed for re-shoots. SPE's wardrobe department also helps productions by making costumes, providing costume rentals and offering preparation rooms for everything from dyeing to storing clothes.