In 1949 Munari designed for the first time a series of “libri illeggibili” (illegible books), which abandoned textual communication in behalf of aesthetic function only. Paper is no longer the support of only text, but it also communicates a message through the format, the colour, the cuts and their successions. The elements that usually set up a book (like the colophon and the title-page) are removed, and the reading seems the execution of a melody, with always different tones during the sequence of the pages.