There is a similar problem with digitized photos, for instance from glass plates. Often they had notes in margins or on the backside, but many scanning efforts didn't take these into account. So a lot is lost forever, either because the originals are destroyed, or forgotten in some archive.
A 2009 paper shows that you can tell blank pages apart from one another by examining them closely under a scanner: <a href="https://citp.princeton.edu/our-work/paper/" rel="nofollow">https://citp.princeton.edu/our-work/paper/</a><p>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.