Leroy has exacting fabric standards: From a worktable in her atelier near the Bastille, she crunched a dry, double-faced crepe between her hands and extolled the sponginess of a cotton viscose. She used bonded poplin on the short sleeves and breast pockets of a classic shirt to give stronger form to an otherwise relaxed shape. Rather than default to a print, she sourced a macro netted cotton with holes the size of euro coins. Stripes became a technical challenge in which knitted cotton alternated with a barely there nylon base. The payoff was high—both the stripes and circles yielded a delicate yet architectural transparency.