Nope, not paper, it's microfiche.
These intriguing photos come from Mickey Smith [1], who's making a photo collection by combing through microfiche located in Minneapolis Libraries. Very cool.

(Oh. And in case you might be too young or have never worked in a Library, here's what it is [2].)
[via [3]]
Links:
[1] http://cheek.blogspot.com/2007/12/mickey-smith-is-currently-taking-photos.html
[2] http://en.wikipedia.org/wiki/Microfiche
[3] http://cheek.blogspot.com/2007/12/mickey-smith-is-currently-taking-photos.html
[4] http://www.rakemag.com/advertising