Oud is the heart of Gulf and modern French-Arabian niche perfumery, the agarwood resin distilled from infected Aquilaria trees and graded by region across Cambodi, Hindi, Lao and Thai. The wing splits between smoky-leather oud, rose-oud, saffron-oud and amber-oud, and rewards wearers who let the resin settle on skin for an hour before judging the composition.