You've seen it before—a sign, a logo, or a headline that feels off, but you can't quite explain why. The letters are all there, spelled correctly, using a perfectly nice font. Yet something makes you wince. Your brain registered a problem before your conscious mind could name it.

That uncomfortable feeling? It's often kerning—the spacing between individual letter pairs. And here's the fascinating part: your brain processes these micro-gaps constantly, evaluating whether text looks "professional" or "amateur" in milliseconds. Bad kerning doesn't just look wrong; it actually creates tiny cognitive hiccups that make reading harder. Let's explore why fractions of a millimeter matter so much.

Here's a fun design paradox: if you space every letter exactly the same distance apart—measured mathematically from edge to edge—the result looks uneven. Your brain doesn't measure spacing with a ruler. It measures the visual area between letters, perceiving shapes as masses of light and dark.

Consider the letters H and O. The H has two vertical stems creating a rectangular negative space. The O is round, with curved edges that create pointed gaps when placed next to straight letters. If you put H-O with identical edge-to-edge spacing as H-H, the O looks stranded—too far from its neighbors. Your brain sees less visual "weight" in those curved-to-straight gaps and interprets this as extra distance.

This is why professional typefaces include kerning tables—hundreds of pre-programmed spacing adjustments for specific letter pairs. The type designer has already done the optical math, tweaking spacing so your brain perceives balance even though a ruler would show "unequal" distances. When these adjustments are missing or overridden, text feels subtly broken.

Takeaway

Visual balance isn't mathematical equality. When adjusting letter spacing, trust your eyes over measurements—if spacing looks uneven, it is uneven, regardless of what the numbers say.

Some letter combinations are notorious troublemakers. Type designers call them "problem pairs," and once you know them, you'll spot them everywhere. The classic villains: AV, WA, To, Ty, and LT. What do they share? Diagonal or overhanging shapes that create awkward triangular gaps.

The capital A is essentially a tent—its angled sides leave wedge-shaped spaces. Place it next to V (another tent, inverted), and you get a canyon between them. The word "WAVE" without proper kerning looks like "W A V E" with letters drifting apart. Meanwhile, combinations like To suffer from the T's horizontal bar hovering over the round o, creating dead space underneath.

Professional designers kern these pairs so letters actually overlap slightly—the V tucking under the A's overhang, the o sliding beneath the T's crossbar. This "collision" that would horrify mathematicians creates the smooth, cohesive reading experience your brain craves. Many free fonts and word processors ignore these nuances, which is why DIY designs often feel amateurish despite using "nice" fonts.

Takeaway

Memorize the problem pairs: AV, WA, VA, To, Ty, LT, and any diagonal-meets-straight combination. When creating headlines or logos, manually check these pairs and tighten spacing until letters feel like they're having a conversation, not standing in separate rooms.

Here's where kerning gets urgent: spacing problems that hide at small sizes become screaming errors at large ones. At 12-point body text, a slightly loose "AV" might pass unnoticed—your brain smooths over tiny inconsistencies when processing continuous reading. But blow that same text up to a 72-point headline, and suddenly that gap looks like the Grand Canyon.

This scaling effect explains why professionals obsess over kerning in logos, billboards, and presentation titles while being more relaxed about email body text. The math is brutal: double the font size, double the visible spacing error. A 2-pixel gap that's invisible at 14pt becomes an 8-pixel chasm at 56pt. Your brain, magnificently attuned to pattern irregularities, catches these enlarged mistakes instantly.

The practical lesson? Every time you increase text size for emphasis—headlines, pull quotes, hero banners—you're accepting responsibility for its kerning. Most design software lets you manually adjust individual pairs (in Adobe products, alt/option + arrow keys). Spending thirty seconds tightening a headline can be the difference between "polished professional" and "made in PowerPoint during lunch."

Takeaway

Treat any text above 24 points as requiring a manual kerning check. The larger your type, the more visible your spacing sins—what hides in paragraphs screams in headlines.

Kerning is one of those invisible skills that separates polished design from amateur attempts. Now that you understand why your brain rebels against bad spacing, you can't unsee it—welcome to the club of people who twitch at movie posters.

The good news: fixing kerning doesn't require design school. Just slow down with headlines, watch for problem pairs, and trust your instincts. If something feels off, tighten it until it doesn't. Your readers' brains will thank you, even if they never know why.