It was to celebrate the 6th anniversary of Dante's death that in 1920 the project for a monumental edition of Dante's work came to life, financed by the lawyer Rino Valdamieri, together with other private investors. Amos Nattini executed the edition: he worked on the illustrations, the typographic aspects, the creation of the characters and the technical aspects. He therefore made 100 watercolors, one for each canticle, which were subsequently lithographed. 1000 copies were printed in hand-made rag paper 140x100 cm with leather cover of white calf. It took 20 years and 7 months to complete the artwork. Nattini also wanted a lectern to contain the three volumes weighing about 27 kg each: it was made by the cabinetmaker Eugenio Quarti, based on a drawing by architects Giò Ponti and Tommaso Buzzi.
Purgatorio, Canto II. Dante meets the musicians Casella and Cato. Nattini depicts a chaotic scene in which male and female figures, completely naked, crowd the lower half of the pictorial space. These bodies are shaped with extreme care and truthfulness. The artist represents souls much closer to physicality than to the spirituality of their condition. Not evanescent floating masses, but solid bodies. Those who listen to the song of the musician Casella are not souls, but people. In the set of figures, rendered in brown colors, the figures of Dante and Virgil can hardly be identified; next to them Casella. On the far left is depicted Cato who, pointing the index finger of his left hand, scolds souls for their negligence. In fact, they are still listening to the song of the musician, while their task is, instead, to go without delay to the mountain of purification.