Why Do Some Words Look Wrong? The Gaps Are Not Equal
By the BrainSnail editorial team. How these articles are written and checked, and how to tell us when one is wrong.
Setting every letter the same distance apart produces text that looks uneven, because letters are different shapes. Adjusting individual pairs is what makes spacing look regular.
Why equal spacing looks unequal
The eye judges the space between letters by the area of white between them rather than by the distance between their edges, and letters enclose white very differently. A capital A slopes away at the top, a capital V slopes away at the bottom, and setting the two adjacent at a standard distance leaves a wedge of white that reads as a gap. Two straight-sided letters at the same distance leave a narrow even channel that reads as tight. Making the visual spacing even therefore requires the physical spacing to be uneven, and adjusting particular pairs is the whole practice.
The pairs that always need it
The problem cases are predictable from the letter shapes:
- •A capital followed by a sloping letter, such as A next to V or W
- •T or F or P followed by a low round or sloping letter
- •A letter with an overhanging arm, such as r followed by a comma
- •Y or V followed by a full stop or a comma
- •L followed by T or Y
- •Quotation marks beside almost anything
How it is done now
The adjustments are built into the font rather than made by hand each time, which is why text set in a well-made typeface looks right without anybody doing anything. A font file contains a table listing pairs of characters and the adjustment to apply to each, and modern formats support tables running to many thousands of pairs handled by rules rather than individually. Software applies them automatically where the feature is enabled, which it is not always, and turning it off in a page layout program produces text that looks subtly wrong in a way most readers notice without identifying. Designers still adjust by hand in headlines and logotypes, where the type is large enough for small errors to show.
Where it came from
The practice began as a physical modification in metal type and the word records that. A piece of metal type is a rectangular block, so letters cannot normally overlap, and a character whose shape needed to project beyond its block was cast with part of the letter hanging over the edge, unsupported, which is what the term originally named. Those overhanging parts were fragile and broke readily, which is why they were used sparingly and why italic faces with many of them wore out faster. Photographic and then digital typesetting removed the physical constraint entirely, which is why modern type can be spaced far more freely than metal ever allowed.
What it is not
Three adjustments to spacing are routinely confused and separating them clarifies what is being discussed. The practice described here adjusts the space between one specific pair of letters. Tracking adjusts the space between all the letters in a stretch of text uniformly, which is used to tighten a heading or to open out small text for legibility, and applying it heavily to lower case is generally regarded as a mistake. Leading adjusts the vertical space between lines and has nothing to do with either. And the width built into each character by the designer is a property of the font that neither of the first two changes.
The takeaway
The eye reads the area of white between letters rather than the distance between edges, so equal spacing looks uneven wherever letters slope or overhang, and particular pairs must be closed up to look regular. Fonts carry tables of those pair adjustments and software applies them automatically where the feature is on. Adjusting all the letters uniformly is a different operation entirely.