Boetti "sent" 25 people on 25 imaginary journeys of tours (artists, friends, even Duchamp who was dead). The only physical clues or witnesses were the letters directed to the 25 addresses, at the various stations. Boetti sent a letter to one of these locations, with an address that did not correspond to the recipient's. Since the travellers could not be found, the letter was sent back to the sender, who photocopied the envelope before placing it inside another (bigger) one. The new envelope was then sent on to the next address for the same recipient, who yet again was unreachable at that address. Each journey ended with the last envelope containing all of the previous ones, returned to the sender, and with the photocopies of the envelopes themselves, documenting each individual stage of the itinerary. Occasionally the envelopes went astray, or the journey was interrupted for other reasons (the attempt to send an envelope to Ettore Spalletti on the Island of Montecristo, for instance, failed several times in a row because the island is not served by a postal service). At the end of the trip there resulted a double "product" of 25 thick envelopes called Postal Journeys and 25 sets of pages called Postal Dossier revealing the inside of the multi-layered envelopes ["cipolle" ("onions") as Boetti called them]. The artist then decided to produce a limited edition of 99 that was never entirely bounded, using the photocopies and illustrating the routes followed on each of the 25 postal journeys.
