A large body of Dettmer's current work is created by altering books, including older dictionaries, encyclopedias, textbooks, science and engineering books, art books, medical guides, history books, atlases, comic books, wallpaper sample books, and others. Dettmer seals and cuts into the books, exposing select images and text to create intricate three-dimensional derivative works that reveal new or alternative interpretations of the books. Dettmer never inserts or moves any of the books' contents. (Moayeri 2008). This process is performed without pre-planning or mapping out the contents before cutting into the book. (Cullum 2010). As he cuts away unwanted material with knives, tweezers and surgical tools, Dettmer stabilizes the remaining paper with a varnish. (Fox 2009). An early example of Dettmer's altered books is his 2003 work, "New International Dictionary", an original 1947 unabridged dictionary sealed and cut to expose images within the dictionary (Sundell 2005, at pg. 70).