The third reason for editing is to make a map more legible. A conventional map, as well as a display on the screen, is a communication medium that graphically conveys to users geographic information. Because of the limited space provided by a map and the large amount of information that is normally shown on it, cartographers use various techniques to enhance the graphic message for easier reading. Cartographic enhancements address the following issues:

Name placement - Text annotations are added to the map to depict some of the feature attributes. For example, we add text to show the names of roads, rivers, buildings, and so on. Names for linear and area features are often curved, and names in dense areas of the map have to be arranged so as to avoid clustering. Contour labels follow special cartographic rules to ensure that they can be read without rotating the map.

Generalization - This is a technique of making use of the limited space available on the map to effectively depict geographic information. At a small scale, features that are too thin or small to be visible have to be exaggerated in size. This expansion could interfere with the surrounding features, and the affected features have to be moved to maintain topological consistency.

Symbolization - Annotation text alone is not enough to represent all the attributes of features. In fact, too many annotations could create clustering. A very effective way of visually representing the attributes is to symbolize the point, line, and area features. For instance, a dashed line can be used to indicate that a highway is under construction, and a double line can be used to indicate that the highway has multiple lanes.

Graticule - A network of grids on a map labeled with coordinates form a graticule, which helps the reading of positions. A map is not just a visual depiction of the geographic features, it is also a database. In order to facilitate geographic feature retrieval and spatial analysis, maps are superimposed with a graticule labeled with coordinates. This allows reading of the coordinates of any point on the map, and when given the coordinates of a feature, the graticule helps the quick location of it on the map. These coordinates can then be used to compute distance, area, angle, and other measurements.

Margin information - Supplementary information about the map, such as its scale, map projection, reference ellipsoid, map identification number, and year of the survey are placed around the margin of the map.

Cartographic enhancements are largely manual operations, and a GIS provides interactive editors for this purpose. There has been considerable research conducted on automating these operations, and some important advances have been made.

When the map is not too dense, name placement can be automated to a large extent. It becomes difficult in a crowded place. An interesting problem regarding name placement is the automatic generation of a label at the visual centre of an area. There are many good techniques for this, and most GIS would provide such a function.

Symbolizing point features and line features can be largely automated. Symbolization of area features mainly consists of colour and pattern filling and are quite easy to automate.

Much GIS software provides the function of generating a graticule automatically. A potential problem here is interference of the grids with names on the map.

Margin information is often quite uniform for maps in a series. They have the same scale, map projection, and so on. Hence margin information as often created as templates which are then superimposed on the maps.