In Cradle to Cradle, authors McDonough and Braungart argue that the conflict between industry and the environment is not an indictment of commerce but an outgrowth of purely opportunistic design.C2C is a biomimetic approach to the design of systems. It models human industry on nature's processes in which materials are viewed as nutrients circulating in healthy, safe metabolisms. It suggests that industry must protect and enrich ecosystems and nature's biological metabolism while also maintaining safe, productive technical metabolism for the high-quality use and circulation of organic and synthetic materials The design of products and manufacturing systems growing out of the Industrial Revolution reflected the spirit of the day-and yielded a host of unintended yet tragic consequences. It calls for a radical change in industry: a switch from a cradle-to-grave pattern to a cradle-to-cradle pattern. It suggests that the "reduce reuse recycle" methods perpetuate this cradle-to-grave strategy, and that more changes need to be made. The book discourages down-cycling, but rather encourages the manufacture of products with the goal of up-cycling in mind. This vision of up-cycling is based on a system of "lifecycle development" initiated by Braungart and colleagues at the Environmental Protection Encouragement Agency in the 1990s: after products have reached the end of their useful life, they become either "biological nutrients" or "technical nutrients". Biological nutrients are materials that can re-enter the environment. Technical nutrients are materials that remain within closed-loop industrial cycles. The book itself is a physical symbol of the changes to come. It is printed on a synthetic 'paper,' made from plastic resins and inorganic fillers, designed to look and feel like top quality paper while also being waterproof and rugged. And the book can be easily recycled in localities with systems to collect polypropylene, like that in yogurt containers. This 'treeless' book points the way toward the day when synthetic books, like many other products, can be used, recycled, and used again without losing any material quality—in cradle to cradle cycles. See also a video with Williams McDonough at TED.