How should I care for a carbon steel Shusui display piece?
Updated Mar 2026
Carbon steel requires modest but consistent maintenance to stay in good condition over time. Apply a thin coat of choji oil or food-grade mineral oil to the blade every two to three months — this creates a protective barrier against humidity and prevents surface rust. Always store the blade inside the saya when it is not being displayed or examined, as exposure to open air accelerates oxidation. Avoid touching the blade surface with bare hands; natural skin oils leave residue that can cause discoloration on high-carbon steel. If you live in a particularly humid climate, consider a display case with silica gel packets nearby to control moisture levels around the piece.