The crimson finish on a Red Blade Tanto is achieved through one of two primary methods: controlled oxidation, which bonds a color layer directly into the steel's surface chemistry, or a specialized heat-applied coating that adheres without filling the fine surface texture of the blade. Neither method is simply paint — both are designed to follow the blade's geometry, leaving details like the shinogi ridge and, on clay-tempered pieces, the hamon fully legible. The result is a finish with visible depth rather than a flat uniform tone, and one that holds up well under standard indoor display conditions when the blade is lightly oiled at regular intervals.