Figure-ground (cartography)

This allows more complex composition techniques such as visual hierarchy to organize these phenomena into clear structures that help readers use the map for its intended purposes.

Many studies have employed different experiments, varying the shades, textures, and orientations of test pictures to determine the best method for figure–ground design with mixed results.

"[3] In 1972, Borden Dent appears to have been the first to use the principles of perceptual psychology to develop a theory of how the figure-ground relationship emerges on maps (as well as Visual hierarchy), and a set of guidelines for design to strengthen it.

[4] He identified heterogeneity (contrast), Contour (strong edges), Area (size) and Enclosedness (closure) as the primary determinants of figure identification, a model that gained wide support, soon becoming a core principle of the cartographic canon found in textbooks (including his own).

He tied it directly to the idea of visual levels, the illusion that some elements on the map appear to float above the page, suggesting that figures are "above" their ground.

In this map, Germany is the most clearly recognizable figure, with everything else (the "faded part") being ground. However, secondary (less prominent but still recognizable and usable) figures include the European Union, the land, the ocean, and the inset map, each with its unique corresponding ground. Some features do not have clear figure-ground contrast, such as Europe (dark green+light green+dark gray vs. light gray+white), and can be difficult to perceive unambiguously.
In this map, figures like Oman and the Arabian Sea are less obvious due to a lack of differentiation. The land and the ocean have strong differentiation, but can be difficult to recognize which is figure because neither is closed. Closure and centrality make Oman easier to isolate as a figure than India.