The more you know about a subject area, the more critical you become. I took broadcasting and specialized in film. I’m no cinematographer, but if I watch a film, and the cinematographer was a hack, it certainly does affect my enjoyment of the presentation.

Let me give you a more concrete example. This is a scanned portion of the first edition hardcover printing of Ken Follett’s novel, The Hammer of Eden:

See anything unusual, wrong, or noteworthy? Here’s a second example from the same source:

How about this one? I fully realize that 99% of you will see no problem, but there is a problem.

The obvious answer is that the letter spacing is a disaster. The second example is far looser, but someone made the unfortunate decision to full-justify the text. I dislike full justification, but that’s not even what I’m talking about.

In both examples, the ‘fi’ letter pair collide. The overhang of the ‘f’ overlaps with the dot on the ‘i’ in both examples. So what are they supposed to do, you ask? Surely they can’t change the letters or space them out so far that the two letters don’t collide. Surely. But they don’t have to.

The printer or the publisher, whoever made the decision, was downright negligent. The solution is well known to those familiar with type. Type designers know of this problem and provide a solution. They’re called ligatures.

Wikipedia defines a ligature as:

In writing and typography, a ligature occurs where two or more graphemes are joined as a single glyph. Ligatures usually replace consecutive characters sharing common components, and are part of a more general class of glyphs called “contextual forms” where the specific shape of a letter depends on context such as surrounding letters or proximity to the end of a line.

Don’t get hung up on the fancy-talk. Concentrate on “Ligatures usually replace consecutive characters sharing common components.” The common components are usually parts that touch, creating an unsightly appearance.

Since Follett’s book doesn’t include a colophon, I don’t know what typeface is used. I’ll continue with a known quantity. Here’s the important part of the first example rendered in Adobe’s Caslon Pro:

The two letters look even worse in Caslon. The angled top of the stem of the ‘i’ does not fit with the crossbar of the ‘f.’ So let’s take advantage of Caslon Pro’s ligatures.

The two characters do indeed look different. They’ve been combined into a single harmonious glyph. They might look odd here, being printed so large, but you’ve undoubtedly come across ligatures in books many times without even noticing. Within their proper context, they’re less noticeable than colliding letters because they’ve been specifically designed to not be noticeable. Rather they carry your eye along, without effort…unlike overlapping letters.

Spoken words sound best when they’re carefully arranged with a rhythm and cadence that pleases the ear. Letters on the page look best when they’re carefully arranged, as well. I don’t mean the words they form, though that’s undoubtedly true. Rather, I mean how each letter fits with the one before and the one after.

Here’s the offending word from the second example, rendered in Caslon Pro with the appropriate ligature:

If you look closely, you can see that the ligature isn’t what I led you to expect. Rather than a ‘fi’ ligature combining two letters, this example has an ‘ffi’ ligature that combines three. The ‘ff’ pair does not actually touch in Caslon Pro. A ligature was still created for it because of the rhythm and cadence I mentioned earlier. It flows better. I think it’s also beautiful. I love how the first ‘f’ isn’t quite as tall as the second. And the tail of the second seems to have the dot from the ‘i’ embedded within it. If you weren’t looking for it, you would likely not notice. But if no ligatures were used, you might. I know I would.

Caslon Pro contains 14 lowercase ligatures, which isn’t an unusually large number for a well designed high-quality typeface.

I called not using ligatures in Follett’s book negligent for a number of reasons. The most obvious is ligatures are included in typefaces these days. OpenType typefaces are capable of storing 65,000 glyphs. The book was printed in 1998 so perhaps they were limited to Type 1 fonts. Even those had a separate Small Caps & Old Style Figures option that included the full ligature selection. It might have cost an extra $100. What’s that in the face of a best-seller from a major publisher? And before you think ligatures are something new, think again. They appeared thousands of years ago. Some modern letters are fusions of separate letters that grew together in writing and were finally accepted as new typographic entities in their own right. Ligatures made the transition to movable type when it was invented in 1450. Early computers did not support ligatures. Later, they had to be substituted manually, and finally the process was automatic.

These days, ligatures have come to the masses. If you’re using a Macintosh, most applications perform ligature substitution automatically, on the fly. This may be true for some applications on Windows systems, but as far as I’m aware, it’s only for more typographically aware software. Even if allowances are made for a book published a decade ago, there is no excuse for a publisher to make this same error today.