The Panathenaic peplos was not an item of clothing in the ordinary sense. It was a civic offering in the shape of a garment, produced by a team of Athenian women and girls, the ergastinai, who began weaving it on the loom roughly nine months before the festival, working under the supervision of the priestess of Athena Polias. Two young girls called arrephoroi, chosen from noble Athenian families and typically between seven and eleven years old, lived on the Acropolis for the duration of their year of service and took part in setting up the loom in a ritual that opened the weaving. The finished cloth, dyed saffron yellow and sea purple, carried a woven scene of the Gigantomachy, the mythical battle in which the Olympian gods, Athena prominent among them, defeated the earth-born giants, a subject that cast the goddess as a defender of cosmic order rather than only a patron of craft and war.
The robe was not sized for a living body. It was made to be draped over, or in some reconstructions hung beside, the ancient olive-wood statue of Athena Polias kept in what later became the Erechtheion, a cult image far older and, to Athenian religious sensibility, more sacred than the chryselephantine Athena Parthenos that Phidias built for the Parthenon itself. Bringing a newly woven garment to that old image every year, or every four years in the grander form of the rite, renewed the city's relationship with its patron goddess in the most literal terms available, clothing her again.