OpenType fonts can have up to ten built-in figure styles. This guide explains what they are, where to find them, and when to use them.
By Bald Condensed
Maybe this has happened to you: you’ve just licensed a font family and, eager to take it for a spin, you notice that the numerals look completely different from the samples you saw on the website. If you get confused by the many styles of numerals available in OpenType fonts, you’re not alone. I’ve been writing professionally about digital typefaces for over a decade, and I still often do a double take when hunting for the figure style I want in the font menu. The issue is that an artistic decision needs to happen with the help of technology—and the confusing setup of certain typographic interfaces doesn’t help. In this edition, we focus on the four basic figure styles.
Why do we even have different types of numerals, anyway?
When Arabic numerals reached Europe in the twelfth century, they soon supplanted Roman numerals and became what we came to think of as medieval numerals or oldstyle figures. So-called lining figures, which correspond with capitals, are more recent: they were introduced into European typography in the late eighteenth century and stem from the tradition of shopkeepers’ hand-lettered signs.
By the nineteenth century, oldstyle figures were largely displaced by lining figures due to the latter’s use in newspapers and advertising; the lowercase numerals became rarer still in phototypesetting and eventually digital fonts in the late twentieth century. Most legacy PostScript and TrueType fonts were outfitted with tabular lining figures. Only a limited number of font families offered so-called Expert Sets, additional fonts holding anything that didn’t make it into the core font, like proportional oldstyle numerals and fractions. Since the early 2000s, however, OpenType fonts have acquired an exponentially larger capacity—currently for over 137,000 characters—with room for several numeral sets. Each has its specific use and can be accessed via OpenType features.
To determine which figure style best suits your needs, ask yourself this: Do the numbers you’re setting have to align vertically or horizontally?
Tabular (tnum) numerals
If your numbers have to align vertically, use tabular figures (also called monospaced numbers in Apple apps). Such figures all occupy identical horizontal spaces. Their monospaced nature makes numbers in consecutive lines neatly align vertically in columns. Vertical alignment is crucial for making information in spreadsheets, financial data, math, and things like lists of dates or phone numbers more readable. In many typefaces, to compensate for the extra white space around its narrow form, the tabular figure 1 acquires a foot serif, or an existing foot serif gets widened.
In some typefaces, the figures occupy identical horizontal spaces throughout all the weights, too. This allows users to change the weight of numerals without disrupting the vertical columns.
Proportional (pnum) numerals
Proportional figures all occupy horizontal spaces that are consistent with their design. Their spacing looks more harmonious, which makes them integrate more harmoniously with the surrounding text. Because they advance at varying widths, proportional figures can’t be used for any application that requires numbers to line up in vertical columns.
Lining (lnum) numerals
If you need numbers to align horizontally, use lining figures. As their name implies, they all have the same height. Lining numerals line up with the capitals (or are occasionally a tad shorter).
Oldstyle (onum) numerals
The name oldstyle figures clarifies neither their appearance nor their purpose; it simply alludes to the fact that they adopt their form from the “old” days of movable type. Because their construction follows the logic of x-height, ascenders, and descenders, they’re suited for mixed-case typesetting (i.e., lowercase with capitals).
It’s easy to understand why tabular lining figures became the default figure style. They offer the best of both worlds, allowing alignment both vertically and horizontally. Their main downside is that they stand out too much in body copy, creating a jarring rhythm for readers.
Historically, Proportional oldstyle figures are the original form of Arabic numerals. They harmonize perfectly with the surrounding text in mixed-case setting. Avoid combining them with all-caps text, though—the numbers will look too small and have parts that stick out.
If you’re setting text in all caps, use proportional lining figures. They’ll align with the surrounding capitals but won’t exhibit unsightly gaps around narrower numerals like 1. Certain typefaces may have lining numerals that are shorter than the capitals.
Tabular oldstyle figures are the least common of the four combinations. They can be useful in addresses where numerals need to harmonize with names, while still neatly lining up vertically.
Default figure style
Type designers decide which type of figure the font should display when a user doesn’t specify any particular style. Their decision is based on the intended purpose of the typeface: text faces often have oldstyle figures set as the default, while sans serifs commonly show lining figures by default, as do many display faces. Because the term “default” is non-specific, there is no way of predicting which figure style this setting will bring up.
The four basic figure styles are universally supported in almost all major apps and browsers, except for only partial support in Adobe Photoshop.
Bald Condensed, né Yves Peters, is a Belgian-based rock drummer known for his astute observations on the impact of letterforms in the contemporary culture-sphere. A prolific writer on typography, he has a singular knack for identifying the most obscure typefaces known to humankind.