I imagine it would very difficult to read these dots from a distance and dynamically. I just mention it because most printed documents already have indentifiers printed on them that don't require seeing individual fibers.
https://en.wikipedia.org/wiki/DARPA_Shredder_Challenge_2011
Fun fact: Otavio Good, who led the winning team, learned about the printer dots on this very site. As I recall, he said that the dots were like a map that let them reconstruct the shredded documents.
Thank you for reminding me, and others, how immediate and obvious success can be.