Postage from England, Ireland, Cumbreland, Scotland, Devland, Munkland, and Sark.  
 
Collect lifelike pieces of Altera by receiving leaves of postage stamps from the countries of Britannia. Each country's leaf contains 6 stamps, colour-coded for continental-based postage rates. Learn about the countries by reading the map plate post of Britannia. These beauties physically encapsulate the scope of the imagination and intentions behind Atlas Altera. 
 
Each postage stamp is designed to be a portal to a faraway country while boasting the cosmopolitan idealism of a the Society of Nation's Universal Postal Service (the SoN's UPS):
The year of issue is encoded in the binary numeral system not so dissimilar to the what was used by Carl Sagan for the Golden Record sent off on the Voyager Missions. 
Price is backed by a continent-based pricing scheme standardized across the globe, represented by a dot-based symbol and the colour of the stamp. 
The issuing country of the stamp is representated by a cultural iconography.
The endonym of the issuing country of the stamp is comprehensible to both outsiders and locals alike: it is rendered through its native script while also being conveyed with the universally accessible International Phonetics script (based on Alexander Melville Bell's Visible Speech)
The country can also be recognized around the globe by its exonyms in the five lingua francas pragmatically recognized by the Society of Nations