Imperial diptych Imperial diptych In Late Antiquity, an imperial diptych is a theoretical type of ivory diptych, made up of two leaves of five panels each and each with a central panel representing the emperor or empress. They are so-named in contrast to consular diptychs. They were produced as unique examples, whereas each consular diptych was produced in large numbers to offer to the emperor on certain occasions, principally a nobleman's entry to the consulship. No complete example of an imperial diptych survives and so their existence is contested. The ivories specialist R. Delbrück has theorised that the 19 surviving fragments of
San Marco Altarpiece of cast shadows towards the bottom edges of the draperies in the painting, which are indicative of how Angelico gave the medieval equation of earthly and heavenly beauty new immediacy by translating it into the rational language of a representational style. In addition, as Angelico implies in other ways, glazing was a technique used to create yet another boundary between the real world and the pictorial illusion. San Marco Altarpiece The San Marco Altarpiece (also known as "Madonna and Saints") is a painting by the Italian early Renaissance painter Fra Angelico, housed in the San Marco Museum of Florence, Italy.