To bring to life the wackadoo cartoon world of Bikini Bottom in “SpongeBob SquarePants: The Broadway Musical,” the designer David Zinn went for a bright, found-object aesthetic that mixes “Pee-wee’s Playhouse,” Etsy craft, classic MGM musicals and acid-house clubland. In this world, a mermaid’s tail is festooned with rubber gloves.

It’s not often that the answer to the question “What are you wearing?” is Target, Party City and Comme des Garçons. “Who can say that?” Mr. Zinn, 49, said, laughing, on a recent backstage tour of his most inventive costumes for the show. “Drag queens and SpongeBob SquarePants, that’s who.”

Mr. Zinn received Tony nominations for both costume and set design, two of the show’s 12 nods.