A 2009 paper shows that you can tell blank pages apart from one another by examining them closely under a scanner: https://citp.princeton.edu/our-work/paper/ ht

A 2009 paper shows that you can tell blank pages apart from one another by examining them closely under a scanner: https://citp.princeton.edu/our-work/paper/ https://citp.princeton.edu/our-work/paper/ So not only is there so much texture there, but even a single manufacturer's individual blank pages differ dramatically because of physical wood fibers within the page.