Knorr's Berlin book - produced in collaboration with L40 -  is the tenth edition in an a potentially global encyclopaedia  of artist books that started in 2007 in Romania. Value-free objects found in public space are inserted between the pages of the book and subjected to extremely high pressure thus including a material portrait of a particular place within it's pages.  Berlin is one of first ‘city books’, produced simultaniously with Istanbul and Los Angele. The books include a DVD documenting the book’s production process.