Kerning, Tracking and Leading: Three Different Spacing Problems

Kerning, tracking and leading all change space, but they operate at different scales. Kerning adjusts a particular relationship between glyphs. Tracking changes spacing across a run of text. Leading establishes the distance between successive baselines. If one word looks broken, a heading feels crowded throughout or a paragraph is difficult to follow vertically, those are three different diagnoses. Naming the affected scale first prevents a local defect from becoming a global adjustment.

Imagine a conference page containing a large title, an uppercase category label and a speaker biography. The title has an awkward gap between A and V. The category label looks cramped across every letter. The biography’s lines sit too close together. Reducing all spacing would improve none of these consistently. The title needs pair-level attention, the label needs a run-level decision, and the biography needs a line-spacing decision informed by its width and typeface.

A font gives each glyph an advance width, which helps determine where the next glyph begins. Kerning can modify positioning for specific combinations so that the visible spaces feel more balanced. Letters with diagonal or overhanging shapes make the need particularly obvious: AV, WA and To are common inspection strings. Equal mathematical distances between bounding boxes do not necessarily look equal because the white space around a diagonal differs from the space beside a straight stem.

The OpenType kerning specification describes the older kern table and notes that sophisticated positioning can use GPOS instead. This matters when troubleshooting: kerning is not simply a universal switch that behaves identically in every font and application. The font must contain appropriate positioning information, and the rendering system must apply it. Modern shaping also handles relationships that should not be reduced to a designer manually moving individual Latin letters.

Consider a fictional poster title, AVENUE TALKS, set at 96 points. Suppose the A–V gap attracts attention while the rest of the title feels balanced. First confirm that kerning is enabled. Compare the application’s font-supplied kerning with any optical option it offers. If a manual correction remains necessary, change that pair alone, using a small increment, then judge the whole word. A trial adjustment of minus 20 units in a thousandths-of-an-em interface equals minus 0.02em.

That number is an experiment, not a recommended setting for every AV pair. At 96 points, 0.02em corresponds to 1.92 points; at another size, the physical distance changes. More importantly, another typeface may already kern the pair appropriately. Do not carry the correction into body copy or reuse it automatically after changing fonts. In a final wordmark, manual pair adjustments may be justified; in an editable article headline, reliable font kerning is usually the more maintainable solution.

Tracking distributes additional or reduced spacing across text rather than correcting one exceptional pair. It is useful for evaluating an uppercase label such as EXHIBITION GUIDE. If every part of that label feels compressed, fixing E–X alone will not address the problem. Try a small positive tracking value across the label, then compare the result at its actual display size. The goal is a coherent word shape, not a sequence of evenly isolated characters.

Suppose the label is 14px and you compare letter-spacing values of 0, 0.04em and 0.08em. The latter two introduce nominal increments of 0.56px and 1.12px respectively. These are starting comparisons, not accessibility thresholds. A condensed uppercase face may benefit from a different choice than a wide sans. Check the spaces between words as well: spreading letters can make the ordinary word space seem relatively weak, reducing the distinction between separate words.

Negative tracking can sometimes bring a large display heading together, but it is a poor way to rescue a paragraph that overruns a fixed box. Tightening an entire biography to remove its final line changes every word to solve a layout constraint. Prefer adjusting the container, editing the copy with permission or revisiting the type size and measure together. Never force a line to fit by overlapping letters or suppressing meaningful spaces.

On the web, letter-spacing is related to tracking but is implemented within a shaping and layout system. The CSS Text specification explains letter spacing alongside word spacing and script-sensitive behaviour. Avoid assuming that spacing appropriate for Latin capitals transfers to Arabic or another connected script. Localised interfaces need language-aware review, not a global branding rule that adds identical spacing to every writing system.

In print composition, leading commonly refers to baseline-to-baseline distance. On the web, line-height establishes line-box behaviour and influences the vertical rhythm of text. A line-height of 1.5 on 18px text produces a nominal line height of 27px. That does not mean there are 9px of plainly visible white space between the letter shapes: ascenders, descenders, font metrics and inline content affect what the reader actually sees.

Consider a 68-character-wide biography set at 18px with a line-height of 1.15. Its nominal line height is 20.7px. If readers struggle to find the beginning of the next line, compare 1.4 and 1.55, giving 25.2px and 27.9px. Keep font size and column width unchanged during this comparison. Changing all three variables at once makes it difficult to identify which decision improved the paragraph.

Now consider a two-line title at 72px. Applying the biography’s 1.55 line-height would create a very different relationship between the two lines. A display heading may need a closer setting, provided ascenders, descenders and diacritics remain clear. Test wording containing those features, not just convenient capitals. Also inspect a headline that wraps to three lines: a setting that looks dramatic on two short lines can become awkward on a deeper block.

When an entire layout feels wrong, begin with the content area and font size, then establish line spacing. Those choices determine the paragraph’s basic geometry. Evaluate tracking only when the whole run needs a different rhythm. Inspect isolated pairs last, particularly in prominent display text. This sequence prevents careful kerning from being invalidated immediately by a font change or a substantial change in size.

Use actual content from the font catalogue to compare candidates rather than relying on specimen alphabets. Include names, punctuation and a long heading. Keep a small record of adjustments with their units: tracking at 0.04em, a heading line-height of 1.1, or a manual pair correction in the layout application’s units. A bare instruction such as “spacing 20” is ambiguous and can be reproduced incorrectly.

Finally, review the result at normal reading scale and after content changes. A title may look excellent when enlarged on a design canvas but uneven at its delivered size. A paragraph may acquire a new final line after a font loads or a translation arrives. Spacing decisions should support those ordinary changes. Kerning repairs neighbours, tracking changes the run, and leading organises lines; treating them separately makes the final composition both clearer and easier to maintain.