In 1949 Munari designs for the first time a series of “libri illeggibili” (illegible books), which abandon textual communication in behalf of aesthetic function only. Paper is no longer the support of the text only, 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 kept off, and the reading seems the execution of a melody, with always different tones during the sequence of the pages. Dominated by visual rarefaction and materials’ experimentation, the production of the “libri illeggibili” has been carried on by Munari all life long. In 1955 some of them have been on display at the MoMA; in its Design Collection are still to see 9 “libri illeggibili”. The Libro illeggibile MN 1 was designed by Bruno Munari for our publishing house in the 1984. In the immediate depth of its colours, it has come to its seventh edition.