Based on Vicentino Ludovico degli Arrighi’s lettering model as used in his 1522 book, La Operina. The revival spans 3 flavors: Romano (simple), Corsivo (more complex), and Fiore (swash). They were merged into one font for the OpenType version, P22 Operina Pro, with Greek and Cyrillics. The version included in macOS (added in Yosemite) is named Trattatello.