Gray rayskin (samegawa) is naturally durable because it consists of calcified nodules embedded in shark or ray skin, but it benefits from occasional care. Wipe the saya with a soft, dry microfiber cloth after handling to remove oils and moisture. If dust accumulates in the textured surface, use a very soft brush — a clean makeup brush works well — to sweep it away. Avoid silicone-based polishes or solvents, as they can discolor the gray finish over time. Store the saya in a climate-controlled environment with moderate humidity (around 45–55%) and keep it out of direct sunlight to prevent fading. A light application of Renaissance wax once or twice a year adds an invisible protective layer without altering the matte appearance.