Artist Nina Katchadourian has spent 20 years working on her 'Sorted Books' project.
The idea is simple: take a collection of books, select a few that work together, and stack them so that their titles become a poem.
But the execution requires a lot of work - the process of creating a cluster of books involves careful sorting, some memory work, and concentration.
She starts each project by examining the collection she's working with, looking at titles and book covers while at the same time trying to remember where each one is.
Katchadourian considers her art to be a little bit like portraiture, with each poem representing an aspect of the collection it's taken from.
According to the artist, different collections lead to very different artwork: when she works with smaller groups of books, she feels as if she's creating an intimate portrait.
Creating poems with the Delaware Art Museum's rare book collection, on the other hand, was very different.
Katchadourian told Slate "she felt as if she was working with a country instead of a person, and it opened up questions about American history, including the treatment of Native Americans."
The project got started back in 1993, when Katchadourian was a graduate student at the University of California - San Diego.
She and a group of friends spent a week at the home of a classmate's parent, working on various art projects.
The library drew her attention, and Katchadourian spent most of the week there.
"You know how when you're in a library and you walk along the stacks of books and turn your head to the side and read the titles? I thought it would be amazing if accidentally the titles formed a sentence, and then I realized I could make that happen," she told Slate.
Now Katchadourian has a book of her own, a collection of images from the 20-year project which is titled 'Sorted Books'.