Well. How one used to marble book covers, that is. I guess this is a classical case of a lost craft. One that few people were even aware of when it was still a thing. You certainly don’t see many books around with these covers and if you do, I’m sure they not hand-made anymore. And in the future, we’ll be able to marble our ebook reader, maybe. :) This is another reason why books are works of art, needed to be preserved...