The aluminum version of the RENDER K has an anodized finish to help protect the body from damage. The brass and copper versions have a raw finish, and will develop a unique patina over time that reflects your use. If you prefer a bright, shiny look, you can maintain the polished finish of your brass or copper pen with a jeweler’s cloth. Should you want to adapt another refill for use with the RENDER K, each pen comes with a short length of poly tubing (plus a spring) that can be cut to make custom-sized spacers.