From J. W. Rinzler Blog:
“With Episode II out the door, Lucas took perhaps a week off and then turned full-time to Episode III, last chapter of the Prequel Trilogy. On Fridays I’d sneak out of publishing for each art department “show,” which one artist described as “a gallery opening every week.” George would go from left to right, scanning dozens of artworks pinned to foam core boards, making comments, perhaps choosing a drawing to be one creature or a particular city or vehicle, or approving for functions unknown. Unlike the artists, I had nothing on the line. I was there only to observe how Lucas worked creatively, building up his story, his visuals, and his ideas in concert with their concepts, generated from what he’d told them about the script, idea, or story the week before: it was a symbiotic relationship. George might mention a volcano planet; someone might paint a strange creature on that planet; George might add that creature to that scene or a different scene.
Lucas was patient, and the artists enjoyed working with him. They kept long hours, often pulling all-nighters fueled by Red Bull to bridge Thursday to Friday. As the concept art department hit full stride, their number grew to about 12. Iain McCaig came onboard early on, welcomed back, a master of character design, who had come up with the look for Darth Maul on Episode I, among others.
While working on the script, Lucas traditionally went on what Jane Bay called his “writing retreat”: that is, he would write in seclusion at home in his converted carriage house from Monday through Thursday, in pencil on his yellow legal pads, taking phone calls only when necessary. On Fridays, he would come in for the art department meeting and the rest of his Lucasfilm business.
As preproduction progressed, Licensing also needed to know about the script, details about characters and creatures and vehicles, in order to initiate product development to coincide with Episode III’s release window. Lucas was understanding of licensing’s needs and those of publishing; after all, he was going to make a fortune off of it. While usually being accommodating, McCallum nevertheless had a great contempt for Lucasfilm Corporate, which he often and mostly referred to as the “Dark Side.” He couldn’t wait for licensing, marketing, PR, and the rest of us leeches to be moved to Big Rock Ranch. The farther away, the better. From what he told me, I gathered he felt that licensing and corporate basically made his job of running the nuts and bolts of production harder, from building up the egos in production/ILM/etc. in the fan magazine (by running articles/interviews on ILMers and actors), to gumming up the works in other ways—for instance, the documentary team would want access to record B-roll, or the development of one creature or character or vehicle might take priority over another, or need to be fast-tracked, because its anticipated manufacturing time would take longer or be more complex, etc.—all of these being things a usual movie production didn’t have to deal with.
If production designer Gavin Bocquet, costume designer Trisha Biggar, or stunt coordinator Nick Gillard were in town, Rick would therefore close the art dept. down to only essential personnel in order to obtain important answers from Lucas. At least once or twice, Rick invited one or two HODs (head of departments) to fly over from the UK expressly and strategically to get those answers. When Rick placed Biggar or Bocquet in a room with Lucas, the latter knew they’d reached a critical juncture; it was Rick’s way of putting pressure on him—because without timely decisions from Lucas, preproduction/production would fall hopelessly and expensively behind schedule, something neither of them wanted.
At some point I asked Rick if I could write The Art of Episode III book, since I was going to all the meetings. He was fine with it, but wanted me to explain to George what I had in mind, briefly. So after one art session on the third floor, Rick re-introduced me. This time, George looked me up and down. I was being scanned while I made my pitch: “I want to organize the art-of book chronologically,” I said (something like this). “We could tell the story of how you and the art department work together, how things slowly come to pass organically. It’ll be a companion piece to the Making of book, by another writer, which he’ll also tell chronologically; I’ll edit that one, and the two books will work together as companion pieces.”
His scan complete, George said, “Okay.””
“McCallum’s professional association with Lucas began with The Young Indiana Jones Chronicles (1992) and Radioland Murders (1994), and continued through the Special Edition release of the Star Wars Trilogy (1997), the prequel trilogy (Episodes I, II, and III, 1999-2005), and most recently Red Tails (2012).” (source: StarWars.com)
J. W. Rinzler used to be a writer and editor at Lucas Licensing. He wrote The Making of Star Wars Revenge of the Sith, The Art of Star Wars Episode III: Revenge of the Sith, The Making of Star Wars: The Definitive Story Behind the Original Film, The Making of The Empire Strikes Back, The Making of Return of the Jedi, and also the comic mini-series The Star Wars and two episodes of The Clone Wars.