How do I care for the purple finish on a ninja sword blade over time?
Updated Feb 2026
Caring for a purple-finished ninja sword blade requires protecting the color treatment while also maintaining the underlying carbon steel against oxidation. The most important care principle for a colored blade finish is to avoid abrasion, which can scratch or wear through the surface treatment. Handle the blade with a soft cloth rather than bare hands, and avoid contact with hard or rough surfaces. After handling, wipe the blade gently with a clean soft lint-free cloth to remove fingerprints and any moisture. Apply a very thin coat of camellia oil or mineral oil and buff away any excess - this protects the underlying steel and is generally compatible with most blade color treatments. Avoid abrasive polishing compounds, which will remove the color finish. For the scabbard, wipe clean with a dry soft cloth when dusty and avoid solvent-based cleaners. Store in a low-humidity environment on an open display rack or in the scabbard. With careful handling and this simple maintenance routine, the purple finish will remain vibrant for years of display use.