Place names and other labels convey important information to the reader about the features on the map. Any features that help orient the reader or are important to the content of the map should be labeled. Descriptive text on a map can include the map title and subtitle, copyright information, captions, credits, production notes, or other explanatory material.
The map title usually draws attention by virtue of its size. It focuses the reader’s attention on the primary purpose of the map. The title may be omitted, however, if captions are provided outside of the image area (Dent, 1985).
Map credits (or source information) can include the data source and acquisition date, accuracy information, and other details that are required or helpful to readers. For example, if you include data that you do not own in a map, you must give credit to the owner.
Use the Text tool to add labels and descriptive text to maps.
Typography and Lettering
The choice of type fonts and styles and how names are lettered can make the difference between a clear and attractive map and a jumble of imagery and text. As with many other aspects of map design, this is a very subjective area and many organizations already have guidelines to use. This section is intended as an introduction to the concepts involved and to convey traditional guidelines, where available.
If your organization does not have a set of guidelines for the appearance of maps and you plan to produce many in the future, it would be beneficial to develop a style guide specifically for mapping. This ensures that all of the maps produced follow the same conventions, regardless of who actually makes the map.
Use ERDAS IMAGINE to make map templates to facilitate the development of map standards within your organization.
Type style refers to the appearance of the text and may include font, size, and style (bold, italic, underline, and so forth). Although the type styles used in maps are purely a matter of the designer’s taste, the following techniques help to make maps more legible (Robinson and Sale, 1969; Dent, 1985).
- Do not use too many different typefaces in a single map. Generally, one or two styles are enough when also using the variations of those type faces (for example, bold, italic, underline). When using two typefaces, use a serif and a sans serif, rather than two different serif fonts or two different sans serif fonts. For example, Sans (sans serif) and Roman (serif) could be used together in one map.
- Avoid ornate text styles because they can be difficult to read.
- Exercise caution in using very thin letters that may not reproduce well. On the other hand, using letters that are too bold may obscure important information in the image.
- Use different sizes of type for showing varying levels of importance. For example, on a map with city and town labels, city names are usually in a larger type size than the town names. Use no more than four to six different type sizes.
- Put more important text in labels, titles, and names in all capital letters and lesser important text in lowercase with initial capitals. This is a matter of personal preference, although names in which the letters must be spread out across a large area are better in all capital letters. Studies have found that capital letters are more difficult to read, therefore lowercase letters might improve the legibility of the map.
- In the past, hydrology, landform, and other natural features were labeled in italic. However, this is not strictly adhered to by map makers today, although water features are still nearly always labeled in italic.
Use Font/Size gallery to adjust the style of text.
Sample Sans Serif and Serif Typefaces
Lettering refers to the way in which place names and other labels are added to a map. Letter spacing, orientation, and position are the three most important factors in lettering. There are no set rules for how lettering is to appear. Much is determined by the purpose of the map and the audience. Many organizations have developed their own rules for lettering. Guidelines that have been used by cartographers in the past are listed as follows: (Robinson and Sale, 1969; Dent, 1985).
- Names should be either entirely on land or water—not overlapping both.
- Lettering should generally be oriented to match the orientation structure of the map. In large-scale maps this means parallel with the upper and lower edges, and in small-scale maps, this means in line with the parallels of latitude.
- Type should not be curved (that is, different from preceding bullet) unless it is necessary to do so.
- If lettering must be disoriented, it should never be set in a straight line, but should always have a slight curve.
- Names should be letter spaced (that is, space between individual letters, or kerning) as little as necessary.
- Where the continuity of names and other map data, such as lines and tones, conflicts with the lettering, the data, but not the names, should be interrupted.
- Lettering should never be upside-down in any respect.
- Lettering that refers to point locations should be placed above or below the point, preferably above and to the right.
- The letters identifying linear features (roads, rivers, railroads, and so forth) should not be spaced. The words should be repeated along the feature as often as necessary to facilitate identification. These labels should be placed above the feature and river names should slant in the direction of the river flow (if the label is italic).
- For geographical names, use the native language of the intended map user. For an English-speaking audience, the name Germany should be used, rather than Deutschland.
Preferred Lettering Positions
Many cartographers argue that all lettering on a map should be black. However, the map may be well-served by incorporating color into its design. In fact, studies have shown that coding labels by color can improve a reader’s ability to find information (Dent, 1985).