What is a book?

Books as material objects span from tomes you put on white cotton gloves before touchng, such as this Taschen book of Hokusai's views of Mount Fuji, to a cheap acid paper Avon paperback of Else Morante's "History: A novel". What's inside the book has no necessary linear correlation with the quality of the book itself as a product of the hand and mind (and technological prosethees) of man (woman, other).