Lots of books made their covers by kraft paper in the library. Reason for cover replacement is to protect for the frailed titles. Or is it for visual anonymity? In beginning of each primary school trimester, we were assigned with new text books. Some students would return the next day, with the text book covered, with different methods. Paper ripped from outdated calendar was a usual choice for its larger format, plus the flip side is blank. Stationary store sold variations of produced book covers in soft and hard plastic; some came with plastic spines.
Factually, the decision to cover text books is additional. The printing press had already layered a thin film before they arrived to our hands. However the decision on puting an extra layer indicated a choice about preservation. At the end of the semester, when they would unwrap the outer layer, the book cover would appear as new.
Some readers have the habbit of buying two copies one title of book at once. Once for underlining, the other to retain original appearence. One day I borrowed a book from the Hogeschool Library, the text was filled with underlines and comments made from pencil. The traces brewed quite some anger, until I used one morning's labor to erase the comments page by page.