Brass is an alloy of copper and zinc. Its surface changes with use. New, it holds a bright golden color. Exposed to air, humidity, and the oils of the hand, oxidation gradually alters its surface — both in color and texture. Areas touched often retain their luster; areas left alone deepen into rich browns and darker tones. The pace and direction of this change vary with environment, so each piece moves toward a state uniquely its own.
OBJJP does not regard this as a flaw. We treat the capacity to change through use as a property designed into the object from the start. No maintenance is required. If you prefer to slow the change, a common metal polish can return the surface close to its original luster.
The change carries the time of the person who uses it. The trace of a hand touched every morning, the humidity of a particular room, the light from a nearby window — these accumulate slowly on the surface, building an expression that belongs to no other piece.
An object arrives complete. Through use, it continues to grow. We choose brass because the material records that process honestly.