The Midori Brass series is a stationery line made of solid brass. This series proudly carries the "ages well"-signature; the longer you use it, the better it becomes. Over time, the copper within the brass alloy oxidizes and your brass item might develop some verdigris (i.e. rust). You could polish your brass item with some metal polish, but we suggest you just leave it, the more scratches, moisty fingerprints and verdigris, the better.