The Petra Project presents a unique record of the stages of development of both the text and the illustrations for the composition of a children's picture book. Kisses from Rosa is based on a real experience from the childhood of author/illustrator Petra Mathers. Although it is very much her own story, perhaps precisely because it is so close to her, "it took over ten years of cutting, changing, and adding to the manuscript, and finally letting it rest in a drawer, until this book came together."[Back flap of book jacket]

Fortunately for scholars of children's literature, Mathers saved the versions of both the text and the illustrations for this book and presented them to the Jane Voorhees Zimmerli Art Museum on the campus of Rutgers University. All of these resources from the museum's collection have been digitalized, and the master digital files used to create this website are housed in the Zimmerli. The Petra Project site brings the entire collection together, allowing users who are unable to visit the museum to explore primary source materials electronically. This is especially important since the physical condition of some of these resources demands limitations on their availability, even within the museum.

The Petra Project captures the kind of records of the creative process that are becoming more and more rare as technologies change the ways people do their work. Increasingly authors do multiple manuscript revisions on the computer, saving only the latest version. This may be an efficient way of working, but it leaves no record of and provides no insight into the creative process.

Correspondence between authors and editors is also now likely to be conveyed in emails which may not be printed or saved. Thus, authors and illustrators working today must make a conscious and deliberate effort to save the versions and variants of their work in its stages of development. Most are so focused on the final composition that they see no purpose in that kind of record-keeping, and some are reluctant to have their preliminary work accessible to others.