Why do collectors prefer a gray finish over a mirror polish?

A mirror polish maximizes reflectivity but can visually flatten the blade's surface, making subtle features like nie, hada (folded steel grain), and the hamon's transition zone harder to read. A gray or stone finish — achieved through a progressive series of abrasive stones or controlled buffing — retains a moderate sheen while preserving surface texture and tonal contrast. Collectors who study their pieces closely often find that a gray finish reveals more information about the steel's internal structure and the quality of the temper line. It also tends to be more forgiving in display lighting, reducing harsh glare that can obscure detail when the blade is mounted in a stand or case.

How should I store and maintain a Gunto replica to prevent corrosion?

Updated Mar 2026

Carbon steel blades - including 1060, 1065, 1095, and T10 variants - require regular light oiling to prevent surface oxidation. Apply a thin coat of choji oil or food-grade mineral oil along the entire blade every two to three months, or more frequently in humid climates. When storing, keep the sword horizontal or slightly elevated at the handle end to prevent oil from pooling inside the saya. Avoid storing carbon steel blades inside a leather saya long-term without periodic airing, as leather can trap moisture. Damascus steel requires the same oil care with extra attention to the layered surface. Display cases with silica gel desiccant packs help manage ambient humidity. Never store any carbon steel piece in a sealed plastic case without ventilation.