Newberry Library discovers it holds the largest example in existence of an extremely rare paper type
[The 49-sheet manuscript is] printed on maguey paper, a type made from pounded agave plants that is so rare that only 10 sheets were known to exist: four at the Library of Congress and six at the National Library of Anthropology and History in Mexico City.
The Newberry Library in question is not in Newberry, it's in Chicago.