Made from brown imported calfskin. The surface is smooth and has a silky feel. It's a thin, slightly stiff leather with a subtle sheen. The sewing thread is linen thread, and everything is hand-sewn, making it durable. The size when open is 253mm wide and 186mm long. A Kodansha Blue Backs 320-page book was used for the photos. By the way, the book's size is 173mm long, 102mm wide, and 15mm thick. It can also be used for paperback novels such as KAPPANOVELS up to about 500 pages (see the last photo). Please note that some tall paperbacks cannot be used. Please check the size. As it is natural leather, there may be scratches, wrinkles, and uneven coloring. Please take a good look at the photos before purchasing. #GenuineLeatherPaperbackCover #GenuineLeatherBookCover #HandmadeHandSewn