"These (books), then, did not cause me a small pain when copying them. As it is, the papyri are completely useless, not even able to be un-rolled because they have been glued together by decomposition, since the region is both marshy and low-lying, and, during the summer, is stifling." (De indolentia 19).
"The subject concerning which you question me was once clear to my mind, and required no thought, so thoroughly had I mastered it. But I have not tested my memory of it for some time, and therefore it does not readily come back to me. I feel that I have suffered the fate of a book whose rolls have stuck together by disuse; my mind needs to be unrolled, and whatever has been stored away there ought to be examined from time to time, so that it may be ready for use when occasion demands." (Seneca, Ep. 72).Though made in passing, Seneca's comments reveal that more is at stake for a book to be usable than merely lasting for many years. Even if a book remains on a shelf in a library, it can become unusable or, at best, very difficult to use because the roll will stick together from lack of use. It would be important then for those who cared for books in collections to exercise these rolls periodically in order to help prevent them from sticking together and decaying as both Seneca and Galen mention.
Clare K. Rothschild and Trevor W. Thompson, "Galen:'On the Avoidance of Grief,'" EC 2.1 (2011): 110-129.
Seneca. Epistles, Volume II: Epistles 66-92. Translated by Richard M. Gummere. Loeb Classical Library 76. Cambridge, MA: Harvard University Press, 1920.