Artist and designer Ben Denzer’s book of American cheese slices challenges pre-conceived notions of what materials can be used to create the parts of a book. It serves as a uniquely interactive form of book in its use of perishable and edible material for its pages. The condition of the cheese slices, despite being filled with preservatives, is highly changeable and unstable. While all materials decay over time, including paper and leather, perishable ones do so at an accelerated rate and are highly susceptible to the temperature and humidity of their environment, especially when kept unrefrigerated. The brownish mold spots emerging in more and more areas of each page ensure that the book’s composition changes and looks markedly altered over time. The effects are mutual and thus highly interactive as well as organic; increased biological growth on its body in response to environmental factors leads in turn to the book of cheese slices posing a threat of contamination to the objects surrounding it. (See Ninety One at Sixty Ninth)