And at the center of the gallery is a quote painted in gold leaf: “Your uniform shouldn’t hide your spirit. It should launch it.” — Kasey Matthews

When a shy gymnast’s handmade leotard goes viral, she must balance the pressure of style with the soul of the sport. Part One: The Sketchbook Kasey Matthews had two loves: the perfect arc of a back handspring and the whisper of silk thread through a needle.

Kasey wasn’t the best tumbler on the team. She was a solid Level 8, prone to overthinking her beam routine. But when she designed? She was fearless.

“You’re changing the culture,” her coach, Ms. Gable, admitted. “But remember: fashion is an extension of the gymnastics, not a replacement for it.” The climax came at the “October Gymnastics Invitational”—an annual meet that was half-competition, half-fashion show. This year, Kasey was the guest designer for the entire team.

Today, the “Kasey And October Gymnastics Fashion and Style Gallery” is a real pop-up exhibit that travels the world. It features leotards suspended from the ceiling on invisible wires, posed as if mid-cartwheel. There are video loops of beam routines slowed down so you can see the fabric ripple.