We made an interesting discovery as we were working with the prints. Many of the prints are clipped together with a cute little paperclip, called an Owl Clip. Here are some of the clips with their beefier, modern-day descendant:
The Owl Clip was first advertised in 1905 by the Owl Supply Co. of Boston and is still produced today by ACCO Brands. The modern ones are 1" long; our antique ones are .75". The Early Office Museum has a whole page devoted to the history of the paperclip, if you are interested in learning more.