Pairing fonts

A quick and easy font pairing starts with selecting one serif and one sans-serif font. We know that serif fonts are often easier for people to read, so they make a great body font for maps with paragraph text, and are often used for natural features on maps. Most have a lovely italic font that makes great water feature labels, and their serifs remind us that nature is often not easily confined to straight lines. For that reason, Baskerville and Garamond and Source Serif Pro, and a number of other great fonts for books and blogs, also work well for map labels.

To get the most out of this pairing, look for sans-serif fonts with similar shapes and visual feels. Try to keep other elements similar. Are the Os rounded or oval? Are the x-heights similar? In this case, the contrast between serif and sans-serif will generally provide all the variation you need, without adding a lot of distraction.

Pairing two sans-serif fonts can be more challenging. Some guidelines include matching a bold font with a light one (which can sometimes be done within the same font family), or a rounded one with a condensed, oval form. Since your contrast needs to be done entirely without the aid of serifs, you'll need to have clear distinctions and roles for each font. Sometimes, type foundries will design a group of fonts specifically to work together, which makes your life easier. Look for who designed the type when browsing font sites, and see if they have made others. There are also numerous font pairing sites that will do the hard work for you, leaving you to select the overall visual impression you like from a selection of well-matched fonts.

Finally, when choosing a font, be sure to explore all of its characters and glyphs to make sure you have what you need. This is especially critical if you are labeling in a language that uses diacritics, which are not always included. And pay careful attention to numbers if you'll be using them in your map. Some fonts that are clean and gorgeous in the letter department have scrunched, hard to read numbers. If you've already downloaded the font, you can launch the Character Map in Windows (Start|Search|Character Map) and scroll through the entire character set.

Of course, you can bypass the whole pairings process and select a font family with lots of options. Font families are a single font, with all of its variations in form, width, and weight. Form refers to roman (regular or upright) and italic (slanted) type, upper and lowercase, and also whether or not a font has a true small caps option. Width refers to the width of individual letters, and falls into three categories—regular, condensed, and expanded or extended, and sometimes additional levels of condensed or expanded.

Weight generally ranges from light or thin to extrabold or black, with one or more levels in between. Some families have more options than others. In the following figure, Open Sans is displayed in a variety of weights and widths, in regular and italic forms. While not all combinations are available, there are enough variations to develop significant hierarchy without ever changing fonts:

While you probably already have quite an assortment of fonts on your computer, you can always add more. There are a number of font sources available on the internet, including Dafont (www.dafont.com) and Font Squirrel (www.fontsquirrel.com). Font Squirrel also has a Matcherator, which allows you to upload an image and identify the font used in it. These sites, and many others, have a variety of fonts with a variety of licensing options, and most have a preview option where you can test out your most challenging labels. Many are free to download, but be sure to check the use restrictions; some are not available for commercial use, some require a small fee to use commercially, and others are completely free to use for personal or commercial applications. It's also important to make sure you get a TrueType (TT) or OpenType (OT) font, as fonts without this designation may not render clearly in your final map. 

One final caveat as you dive down the rabbit hole of font selection—obey the three font rule. Maps should never have more than three distinct fonts, and preferably only two, plus a fancy title. More than that, and your map reader is going to feel overwhelmed.