RCR Arquitectes — the Catalan Pritzker laureates from Olot — build almost entirely in coarse weathering (Corten) steel, inside and out. The plate oxidizes to a dark rust-charcoal and is set against dramatic black voids, echoing Pierre Soulages' near-black outrenoir at the Rodez museum.

This system distills that material language: a soot-dark steel-void ground, matte aged-rust surfaces, hard folded edges, and spare condensed technical type. Nothing glossy, nothing bright — only oxidized mass and deep shadow.