If you like conservation of organic materials, or tricky treatments, take a look at this lighthearted but interesting article. A couple of the works depicted do look unrestorable, and are even being called "self-destructive" in the article.
The Getty kouros: a modern creation? - The refurbished galleries of the J. Paul Getty Museum no longer include the Getty kouros, a sculpture purchased in 1985 (Christopher Knight, "Something's ...
14 hours ago