In the opening scene of Ryan Murphy’s latest FX show, Feud: Capote vs. the Swans, a distraught Babe Paley, played by Naomi Watts, pulls her friend and confidant Truman Capote (Tom Hollander) into her sitting room to unload about the latest transgressions of her husband, Bill Paley. As she laid bare the gory details, all I could look at was the room—a recreation of the one Billy Baldwin conceived for the real-life Babe’s St. Regis apartment, with walls curtained in a pleated tobacco-brown Indian calico cotton, block-printed with pale pink flowers. Legend has it that Baldwin snagged the textile for just $2.50 (about $22 today) a yard. The ruched room felt intimate and cozy yet still chic—as if it was specially engineered for sharing secrets.

A recreation of Babe Paley’s Billy Baldwin–design sitting room for the sets of Feud: Capote vs. the Swans, a new FX show directed by Ryan Murphy.

Eric Liebowitz/FX

Fabric-sheathed spaces like this one—often dubbed tented rooms—have a rich history in 20th-century decorating. Babe’s Billy Baldwin version relaunched a vogue for this style in the 1950s (Napoleon I had experimented with the look, employing a luxe riff on military tents, more than a century prior at his residence, the Château de Malmaison) and decorators like Renzo Mongiardino, David Hicks, Francois Catroux, and others put their own spins on the swaddled room.

But recently—shall we call it the Swan effect?—more contemporary spaces have been embracing the timeless trick. There are different versions: Sometimes fabric starts at the ceiling and cascades to the floor. In other executions the textile is pleated or ruched tightly between crown molding and baseboards, adding a luxurious effect that is more textural and less tent-like.

Finely pleated fabric lines the television room at Marella Agnelli’s 18th-century retreat in Northern Italy.

Gili Oberto