As mapmakers, we may be tempted to simply jump in and choose a font that looks right for our map, but an understanding of some key elements of letterforms can help define why a particular font works with the rest of our map elements or not. While there are many components to letterforms, for our purposes, we only need to concentrate on a few, shown in the following figure:
Picture a sheet of notebook paper. The light blue lines printed on it correspond to the BASE LINE and the CAP LINE in the preceding figure. Ascender and Descender often extend over and under these lines, which can sometimes conflict with other map features (if too extensive), and can impact legibility in blocks of text. The X-height is the height of the body of a lowercase letter, which, in part, helps determine the visual weight...
