Gone with the Wind (1939)

Scarlett O'Hara's green curtain dress, worn by Vivien Leigh Walter Plunkett's design turns a plot point into a costume. Broke after the war, Scarlett has a gown made from the drapes at Tara so she can face Rhett looking prosperous, and the dress has to read as an act of desperate pride rather than a couturier's work. That tension is what makes it memorable. On screen it was not real curtain fabric but green velvet treated to look aged and sun-worn, and it was built to last only as long as filming, which is why the surviving dress later needed restoration.