Calamo fountain pen ink (2.4 oz) is available in various color formulations: Blu della Robbia (deep blue), Terra di Siena (sepia), Rosso Fiorentino (red finish), Verde Muschiato (green musk), Zafferano (golden yellow), and Borgogna (deep red). The glass of Calamo bottles is treated to protect the ink from the deterioration caused by exposure to the light. This ink bottle has been developed for Netto, Stipula’s revolutionary system for a clean filling to the last drop.