It was started in 2019 when Winterthur staff members Melissa Tedone and Rosie Grayburn identified a book containing Paris green in the institution's collection.
[2] In 2019, whilst conserving one of the library's books, the 1857 Rustic Adornments for Homes and Taste, she noticed through a microscope that fragments of the green pigment-dyed starch used to strengthen the bookcloth were flaking away.
[4] Paris green bookcloths are unlikely to be a risk to the general public, but they might cause arsenic poisoning in those who handle the books frequently, such as librarians and researchers.
[5] Shortly after starting the project Tedone and Grayburn identified nine further books from the Winterthur collection that contained arsenic.
[2] The project attempts to identify individual editions of historic books that contain hazardous materials such as arsenic.
[2] The project advertises itself with bookmarks showing examples of books containing Paris green; these have been sent to libraries in 49 US states and 19 countries abroad.