Style: Scale bars are almost always black, or in some instances, dark gray, in color. The font used should conform to the other fonts used on the layout. Several layout styles are possible depending on the space allowed within your layout. The more compact form of the scale bar is used more often on modern maps, whereas the more linear form is a relic from previous decades (see Figure 3.9).
Either format is acceptable, though one should tend toward the compact form since it is more balanced and modern. As mentioned earlier, multiple unit scale bars are sometimes required or beneficial. In this case, we can simply show two separate scale bars with the different units, but place them close enough to one another to maintain an orderly looking layout (see Figure 3.10).
You might also want to note the map scale as a representative fraction (e.g., 1:24000) in the same visual space as the scale bar as in Figure 3.11.
An uncommon way of depicting scale, but still worthy of note if the data is especially suited for it, is to show the scale in area form. Many population density maps, for example, are shown in square mile or square kilometer units and would be ideal for this kind of scale graphic. Additionally, a map with buffers around points at certain distances could also use a scale graphic. See Figure 3.12 for examples. If these types of scales are used, they ought to be shown in conjunction with a conventional scale bar as well.
FIGURE 3.9