MILLENIUM CASE STORAGE SOLUTION. The Mill Case M is a rigid archival individual clear acrylic case for Golden Age, Silver Age, UK, Moden Age comics and magazines. One size fits all. Protect spine from creases. Clam-shell design minimizes dust. Professional presentation. Convenient handling. Millenium case provides the ultimate protection and storage for your treasured books. Sold in a set of 4 pieces.