Rotterdam-based, talented designer Reinier de Jong has designed an extending bookcase.
REK Bookcase consists of five parts that slide out to accommodate books in the resulting voids as the user accumulates them. REK grows with your book collection, the more books you get, the bigger the bookcase gets. REK will always look full, regardless of the quantity of books.
Also the books can be arranged according to their sizes.
The narrow spaces on the bookcase are excellent for magazines or such.