The term refers to tanto collectibles fitted with a darkened tsuba - the hand guard - typically finished in blackened iron, oxidized alloy, or lacquered metal. This distinguishes them from natural iron or polished silver-tone guards. The black tsuba creates a high-contrast focal point between the blade, the ito wrap, and the saya, giving the piece a more unified, dramatic presentation. Historically, darkened fittings were associated with subdued, purposeful aesthetics favored by samurai who preferred understated elegance over ornamentation. On a display piece today, that same restraint reads as sophisticated and intentional.