[zwirbl]

A reused manuscript page is called a palimpsest and often the scraped off text can be recovered. Some of Archimedes writings actually survived this way https://en.wikipedia.org/wiki/Archimedes_Palimpsest

[unwind]

Obligatory shout-out to the novella of the same name, by HN user (and, obviously, Actual Author) Charles Stross.

[1]: https://en.wikipedia.org/wiki/Palimpsest_(novella)