Porthole
Porthole. The opening in album pages for inserting coins or small medals. Portholes are cut entirely through the album page so the reverse can be viewed by turning over the page. (The opening for large medals in cases is called a well; wells are not usually cut through, the medal has to be removed to view the unexposed side.)
excerpted with permission from
An Encyclopedia of Coin and Medal Technology
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor