Iris — technically "orris" once its root has been dried and aged for years before processing — is one of the most expensive raw materials in perfumery, and it's easy to smell why once you've encountered it. On its own it reads earthy, slightly woody, and unmistakably powdery, like the inside of an old compact or a fresh dusting of talc. Paired with musk, vanilla, or other florals, it becomes the backbone of what perfumers call "powdery" fragrances — soft, velvety, and quietly nostalgic in a way few other notes manage.