REK is a flexible bookshelf designed by Reinier de Jong. The versatile bookshelf features zigzag shaped parts slide in and out to accommodate books. The size of the shelf can be changed according to number of books, the more books the bigger the bookcase gets. When not needed, it can be completely folded to save some space which also makes it easier to transport. The bookcase has shelves of different sizes where you can arrange books according to their sizes. It makes it easier to sort out the books based on categories etc. Check out the pictures.
Image Courtesy: Reinier de Jong