For most people, print is permanent, but a new printing technique may add a sense of urgency to reading the printed word. If an Argentine publishing company has its way, the shelf life of a printed book will be short. The company has printed a book in ink that disappears in two months after it is exposed to sunlight and air. Eterna Cadencia printed a book called “El Libro Que No Puede Esperar”. Translated, it means “The Book that Can’t Wait”. The publisher believes you will be forced to read a book you bought if you know it is going to disappear in two months.