Diego Ribero was a Portuguese who had sailed to India with Vasco Da Gama and Alfonso de Albuquerque. He entered the service of Spain and assumed responsibility for maintaining the padron real—the master chart which incorporated geographical reports from Spanish ships when they returned to their home ports. It is the first map to show the true size of the Pacific Ocean. It is also the first sea-chart to embody cosmographic information: a calendar, a quadrant, an astrolabe and a declination scale, with texts explaining their use. The map is in the Biblioteca Apostolica in the Vatican. The map shows the east coast of North and South America, the Atlantic Ocean, Europe and Africa and Asia to the east of India. The compass roses and astrolabe  pictured on the stamp are from the lower right hand corner of the map.

    The full title of this world map is Carta Universal En que se contiene todo lo que del mondo Se ha descubierto fasta agara: Hizola Diego Ribero Cosmographo de Su Magestad: Año 1529. La qual Se devide en dos partes conforme a la capitulcio que hizieron los catholicos Reyes de españa, y El Rey don Juan de portugal e la Villa de Tordesillas: Año 1494 [General chart containing the whole of the world that has hitherto been discovered; complied by Diego Ribero, cosmographer to His Majesty, in the year 1529, which is divided into two parts according to the agreement made by the Catholic Majesties of Spain and King John of Portugal at Tordesillas, A.D. 1494].