Book Design 102: Anatomy of a Typeface

This series approaches book design through the basic fundamentals of typography. In our previous post, we discussed classifications of typefaces. Here’s where things get sexy. Or, depending on personal preference and temperament, unfathomably tedious. So let’s keep it simple.

Point Size Versus x-height

Type is typically measured in points (a point being 1/72 of an inch). In the days of metal type, a font’s point size referred not to the height of any particular character, but to the uniform height of the blocks of lead on which each character sat. Today, because metal type is all but obsolete, point size is a fairly capricious metric. In the digital realm, the size of a typeface refers, somewhat vaguely, to the distance from the tip of the tallest character to the bottom of the lowest character—plus a little extra.

A more concrete metric, and a crucial one in determining how a given typeface will express itself within a body of text, is x-height. This refers to the height of a lowercase “x” relative to the overall height of a letter. Generally speaking, typefaces with high x-heights are more striking, while a low x-height can give a font a more delicate appearance. (Another generalization: sans-serif typefaces tend to have higher x-heights than serif typefaces.)


The Baseline

All type is set on a baseline, a (usually) flat, horizontal, and invisible line above or below which all other elements fall. Typographers use x-height because a lowercase “x” has a flat top and bottom and thus sits nice and square between the baseline and x-height line—an “x” also contains no ascenders or descenders.

  • Ascender: any portion of a lowercase letter that rises above the x-height. Examples include the upper half of an “h,” “f,” or “k.”

  • Descender: any portion of a lowercase letter that falls below the baseline. Examples include the lower half of a “y,” “g,” or “j.”

If you look carefully, you’ll notice that letters with curved tops and bottoms (an “o” has both; “u” and “n” have one each) fall slightly outside the x-height/baseline field. This creates an illusion of consistency—if an “o” were precisely the same height as an “x,” the “o” would appear shorter. The same is true of capital letters; for example, an uppercase “S” is slightly taller than an uppercase “F.” (Cocktail party fodder: uppercase letters are thusly named because they were typically stored in cases above their lowercase counterparts in lead-era print shops. More cocktail party fodder: upper- and lowercase letters are also called majuscules and minuscules, respectively; just be sure you’ve truly run out of anecdotes before brandishing this one.)


Anatomy of a Typeface

The hoard of terms used to describe the elements of a typeface is vast; some terms are even exclusive to single letters and even subclassifications of single letters. A lowercase, double-story “g,” for example, is unique in possessing an ear, a neck, and a loop. And only an “S” has a spine. Let’s focus, then, on a few basics—the terms you won’t ever use but might consider thinking about using if your majuscules/minuscules quip goes over well.

  • Stem: a primary vertical stroke; an “l” is all stem

  • Bowl: a curved stroke that creates and encompasses some negative space

  • Counter: the negative space encompassed by a bowl

  • Aperture: a counter not fully closed off by its bowl; a counter with an opening

  • Shoulder: the curved top of some lowercase characters

  • Terminal: a curved, serif-free end of a stroke

  • Finial: a tapered terminal; a fairly seductive term

We’re skipping over arms, legs, beaks, tails, joints, crotches, eyes, feet, hairlines, and even tittles, the point being: not all information is worth knowing. But it’s sexy, right? Clearly it is. Actually, on second thought, you should probably come away from this knowing, if nothing else, what a tittle is: it’s a dot, as in the thing found at the top of a lowercase “i” or “j.” You’re welcome.


And, Finally, Ligatures

One area where typefaces tend to exhibit a bit of heightened flair and seduction is in ligatures, which are created anytime two characters touch. (The term comes from the Latin ligātura, “to bind.”) Most advanced typesetting applications (Microsoft Word and Adobe InDesign among them) create ligatures automatically, though in the days of lead type, where letters could not physically overlap, special characters had to be created. A lowercase “f” is commonly involved in ligatures due to its overhanging ascender; you’ll often see fl, ff, fi, fj, fa, or f-just-about-anything set as a ligature. Practically speaking, ligatures are created to avoid unwanted “holes,” or negative spaces, between characters that would interrupt a reader’s flow, though they also give type designers (as well as typesetters) a chance to have a bit of fun. A decorative ligature, when used nimbly in a line or field of serif text (decorative ligatures are common to the point of ubiquity in script typography and are almost never seen in sans serifs), can add just the right amount of sex appeal, like a splash of bourbon in your coffee or, you know, whatever you’re into.


I hear you crying foul; I do. I hear you contending with righteous indignation that the alabaster curve of your college sweetheart’s unclad flank is (or anyway was at one time) far more sensual—far more sexy—than a nimbly placed ligature, or an italic ampersand (I’m picturing Garamond’s), or a minuscule double-story “g.” I’d ask you not to kid yourself. Garamond and his eyes, shoulders, arms, and legs have been turning heads for centuries, and his tittles will be here long after we’ve all sighed our last. In subsequent posts we’ll explore how these lovely little characters can work together to create a legible and inviting body of text.

Next up: “Typesetting Basics.”