How do I maintain a black blade treatment long-term?
Updated Feb 2026
Maintaining a black blade treatment long-term requires protecting the underlying carbon steel while preserving the black surface treatment. After every handling session, wipe the full blade with a soft lint-free cloth to remove moisture and fingerprints - skin oils and moisture are the primary threats to both the carbon steel and the black surface treatment. Apply a very thin coat of camellia oil or mineral oil to the full blade surface and buff away excess, being careful to use only light pressure to avoid abrasion of the black treatment. Never use metal polishing compounds or abrasive materials on a black blade treatment, as these will remove or damage the color surface. Avoid prolonged direct sunlight exposure, which can cause black blade treatments to fade or develop an uneven tone over time. Store in the scabbard or on a display rack in a stable-temperature, low-humidity room. Inspect the blade surface periodically for any signs of the underlying steel developing oxidation spots through the black treatment - if rust spots appear, address them immediately with oil treatment to prevent further oxidation.