Having expressed an interest in comics and science fiction, Vadim was hired to direct Barbarella after producer Dino DeLaurentiis purchased the film rights to the comic series. Vadim attempted to cast several actresses in the title role (includingVirna Lisi, Brigitte Bardot, and Sophia Loren) before choosing Fonda, his then-wife. A friend of Vadim's, Terry Southern, wrote the initial screenplay, which changed considerably during filming and ledto seven other writers credited in the final release, including Vadim and Forest, the latter of whom also worked on the film's production design. The film began shooting immediately following the completion of another DeLaurentiis comic adaptation, Danger: Diabolik, with both films sharing several cast and crew members.
Jane Fonda’s costumes for the film were the work of Jacques Fonteray and fashion designer Paco Rabanne. Fonteray would later work on films such as Moon Raker and The Party while Rabanne’s fashion forward designs became renowned for their bold details. Influenced by armour as well as the 1960s women’s liberation movement, quite a few of the designs included non-traditional materials.
Source: Wikipedia.