Keys, Signs, and Measurements
This layer includes the map's keys (one for symbols, one for determining water depth), latitude and longitude lines, and significant place names. This layer would have been essential for contemporary readers, especially ones with no first hand knowledge of the space represented. By connecting the maps detail with its use of standard European map tropes, readers could contextualize and situate the land depicted in the map.
Projection and latitude and longitude lines
This layer shows the lines that the mapmaker used to design the projection. This is an important backbone to the map as it shows how Vespucci planned the unusual polar projection and the lines would have provided him with guidelines for where different features are. The latitude and longitude lines also allow the viewer to orient themselves in regards to which part of the globe they are seeing. These lines are very obvious and visually striking, especially in the large spaces around the globe.