To provide the best protection for your coins we recommend the AIR-TITE coin holders. They are made from clear acrylic plastic with a non-yellowing agent. The insert that fits around the coin (available in BLACK or WHITE) is manufactured from a polyethylene material that contains no PVC or other materials which are harmful to coins and medallions and are completely inert. Because of the wide range of sizes available they are a great way to package and preserve all of your more valuable coins.