A book of the Bibliothèque de la Pléiade. The thinness of bible paper allows books with a large number of pages to remain fairly compact.
Bible paper is a thin grade of paper used for printing books which have a large number of pages. Technically it is called lightweight offset paper and is a type of woodfree uncoated paper. This paper grade often contains cotton or linen fibres to increase its strength in spite of its thinness.