When George Lucas conceived “Star Wars” in the early 1970s, he had to create an entirely different look for an entirely different galaxy. That included the costumes. The film’s production illustrator, Ralph McQuarrie, did the groundwork. The execution went to John Mollo, a British military illustrator and cinematic wardrobe consultant who would win the 1978 Academy Award for Best Costume Design for Mr. Lucas’s space epic.

On Dec. 11, Bonhams will auction Mollo’s original sketchbooks for “Star Wars” and its sequel, “The Empire Strikes Back,” in its “Designing an Empire: The John Mollo Archive” sale. The books for the first movie are expected to fetch $130,000 to $190,000, the sequel, $100,000 to $160,000. Also up for grabs are sketches and ephemera from other Mollo movies including “Barry Lyndon,” “Alien,” “Chaplin” and “Gandhi,” for which Mollo won his second Oscar.

The time pressure on the first “Star Wars” was intense for Mollo, who died last year. “I think my father put it all together in six weeks,” Mollo’s son, Tom, said in an interview earlier this month. “He always said he found it frighteningly difficult working with people who were indecisive, and Lucas was not indecisive. He’d put the sketches before him and he’d say yes or no.”

Lucas “said in a memorable understatement, ‘I don’t want anyone to notice the costumes,’” John Mollo wrote in a foreword to “Star Wars Costumes: The Original Trilogy” by Brandon Alinger . “Unlike period films, where there are limits to what is historically correct, there are none in science fiction, and the director can ask for any outlandish thing he wants with the cost being his main handicap. George wasn’t like that. He strongly believed that the costumes should be real clothes, and that if they were noticed too much they would distract the attention of the audience .”