Ulla Klückmann's collection of around 920 pop-up books was donated to the International Youth Library in 2013. The collection presents a variety of the themes, mechanisms, styles, times of origin and aesthetic concepts of three-dimensional book art.
The collection includes pop-up non-fiction books about the human body, animals, dinosaurs, cameras, space travel, robots and architecture. Ghost houses, ghost and horror stories also unfold their effect in this medium. In addition to classics such as fairy tales, Alice in Wonderland, Moby Dick, Winnie the Pooh, Little Polar Bear, Wizzard of Oz, and others, whose stories are illustrated by pop-ups, there are works of paper art ranging from Lothar Meggendorfer's folding and drawing books to works by Robert Sabuda, Ron van der Meer, and David Carter.
Some of the books, when opened, allow underwater sounds, whale songs, jungle sounds or birdcalls to accompany the three-dimensional scenes.
The collection is catalogued in the OPAC of the International Youth Library.