But the judges agreed with Lucasfilm's lawyers that Ainsworth had violated Lucas's copyright in the United States by selling costumes there.
Ainsworth's lawyers said the ruling means he can continue to make and sell the replicas, but not export them to the US
The designer said he was delighted.
"I am proud to report that in the English legal system David can prevail against Goliath, if his cause is right," Ainsworth said. "If there is a Force, then it has been with me these past five years."
Lucasfilm said that "unfortunately" the court had upheld an "anomaly of British copyright law under which the creative and highly artistic works made for use in films - which are protected by the copyright laws of virtually every other country in the world - may not be entitled to copyright protection in the UK."
The eminent Supreme Court judges may be experts in law, but their ruling revealed gaps in their knowledge of science fiction. The judgment said the Star Wars movies are set "in an imaginary, science-fiction world of the future."
Film fans know that they take place "a long time ago in a galaxy far, far away."
-AAP