Portolan Chart of the Black Sea

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Information design is vital to clear and efficient communication and cartography has illustrated the importance of visual communication throughout history. Before printing allowed for mass production of visual information design, cartographers had to design, illustrate, and annotate maps by hand. Portolan charts came about around the mid-13th century from the development of compasses and their increasing distribution in the Mediterranean and feature coastlines and straight rhumb lines that visually represent navigational sailing instructions through geometrical calculation. While mainly used for navigation, Portolan charts also functioned as decorations when created with more ornamentation. 

These charts feature the names of ports written along the edges of coasts to describe their location based on the navigational lines across the chart without obscuring important information. The handwritten annotations on the map change size based on the location they describe with regional titles being larger than individual port titles allowing for greater clarity in navigation as the lettering hierarchy ensuring that map readers could refer to the proper locations during their travels.

portolan chart of the black sea
Source: www.loc.gov
portolan chart of the black sea