A book becomes rare because there is something about it which makes it unique, important, or difficult to obtain. Examples include first editions, signed or inscribed copies, books created with particular artistry or new technologies (for instance, a manuscript illuminated with miniatures which complement calligraphic text), objects representing significant historical moments or settings, or artifacts made of interesting materials (paper, parchment, vellum, stone, or clay). Some rare books in the Cushing Memorial Library include Shakespeare's Second Folio from 1632, a fifteenth century illuminated Book of Hours, and many large plate books containing images of Native American culture, ornithology, and images of Western exploration.  A book printed before the end of 1500 is called an incunabulum, from a Latin word meaning "from the cradle," suggesting that it was created during the infancy of print technology.  Cushing Library holds a strong collection of these examples of early printing.

Items from these collections can be viewed in the Kelsey Reading Room. Please note that permission from curators may be necessary, in infrequent circumstances, before viewing some material. This is to protect especially fragile items.