It's nice to know that the Supreme Court gave careful consideration to this case, with much inside knowledge (page 17, my emphasis):
Star Wars may have been a cinematic blockbuster, but its costumes were never high art – a view now confirmed by the supreme court, which has ruled that an imperial stormtrooper's helmet from the movie is not a piece of "sculpture".
The decision opens the way for Andrew Ainsworth, an English prop designer, to carry on selling outfits for up to £1,800 each to customers in Britain but it exposes him – and other UK manufacturers – for the first time to claims of infringement of foreign copyrights in British courts.
Not being a work of art means that any enforceable UK design right in the helmets expired after 15 years.
43. This is quite a puzzling point. The Star Wars films are set in an imaginary, science-fiction world of the future. War films set in the past (Paths of Glory, for instance, depicting the French army in the first world war, or Atonement depicting the British Expeditionary Force at Dunkirk) are at least based on historical realities.Set...in the future? Er...no: