I used to think letters were just shapes.
Then I spent three months watching a type designer named Maria Doreuli obsess over a single junction—the place where the curved bowl of a lowercase ‘a’ meets its vertical stem. She’d zoom in until the pixels became galaxies, adjusting the connection point by fractions of a unit I didn’t know existed. “This is where the letter either holds together or falls apart,” she told me, her screen glowing at 2 AM in her Brooklyn studio. She wasn’t being dramatic. The way typographic elements join—what designers call ‘joints’ or ‘connections’—literally determines whether a letterform maintains structural integrity or collapses into visual chaos. I’ve seen fonts that look fine at 72 points disintegrate into mush at 12 because someone didn’t understand how serifs need to meet stems, how curves must transition into straights, how the stress of a stroke distributes force across a glyph’s architecture.
Anyway, turns out letters are basically tiny buildings.
The physics of it gets weird fast. When you connect two strokes in a typeface—say, where the arms of a capital ‘K’ meet its spine—you’re creating what’s essentially a load-bearing joint. Except instead of supporting physical weight, it’s supporting optical weight, which is somehow more finicky. If the angle is too sharp, the junction creates a visual “trap” where ink pools in printing or pixels blob on screens. Too shallow, and the connection looks weak, like the letter might shear apart. Type designer Cyrus Highsmith once described it to me as “managing tension you can’t touch,” which sounds like therapy-speak but is actually precise. The human eye detects structural instability in letterforms the same way it registers a crooked picture frame—something’s wrong, even if you can’t articulate what.
The Geometry of Where Strokes Actually Meet Each Other
Here’s the thing: most joints in typography aren’t actually joints.
They’re optical illusions. When you look at where the horizontal bar of a lowercase ‘t’ crosses its vertical stem, you’re seeing what appears to be a simple perpendicular intersection. But zoom in on a well-designed typeface and you’ll find the crossbar doesn’t actually hit the stem at a 90-degree angle—it’s been subtly adjusted, maybe 87 or 93 degrees, to compensate for how your brain processes vertical versus horizontal information. Matthew Carter, who designed Verdana specifically for screen rendering, told The Atlantic in 2019 that he spent weeks calibrating these micro-angles because “a mathematically perfect connection looks wrong to human perception.” The stem might be slightly thicker where the crossbar meets it, or the crossbar might taper just before contact. These adjustments—called “optical corrections”—are what separate functional typography from the stuff that makes your eyes tired after three paragraphs.
How Curves Decide to Become Straight Lines Without Anyone Noticing
The hardest joint is the one between a curve and a straight.
I guess it makes sense—circles and lines speak different geometric languages, and forcing them to shake hands creates problems. In a lowercase ‘n’, the curved entry stroke has to transition seamlessly into the vertical stem. Do it wrong and you get a visible “kink,” a moment where the curve hesitates before committing to straightness. Type designers use something called a “Bézier curve” to manage this transition, plotting control points that dictate exactly how the curve accelerates into the straight. Gerard Unger, the Dutch designer who created Alverata, described the process to Typographica as “teaching water to become ice while it’s still moving.” I’ve watched designers spend hours adjusting four control points to make this transition invisible. The goal isn’t smoothness exactly—it’s inevitability, making the joint feel like the only possible solution.
Why Serifs Are Basically Structural Buttresses Made of Negative Space
Wait—maybe I’m overthinking this, but serifs exist primarily as joint reinforcement.
Those little feet at the ends of letters in fonts like Times New Roman or Garamond aren’t decorative. They’re load distributors. When a vertical stem meets the baseline—the invisible line letters sit on—the serif spreads the visual weight across a wider area, preventing the optical equivalent of a stress fracture. It’s the same principle medieval masons used with flying buttresses on cathedrals: you can’t just pile weight onto a single point and expect it to hold. In typography, this matters most at text sizes, roughly 8 to 14 points, where joints become vulnerable. A sans-serif font like Helvetica handles these connections differently, using subtle weight variations and carefully calculated terminals (the ends of strokes) to acheive the same structural stability without the serif apparatus. Neither approach is “better”—they’re just different engineering solutions to the joint problem.
The Part Where Ink Spread Used to Ruin Everything Until Designers Got Clever
Honestly, the whole joint situation got more complicated with printing technology.
When Gutenberg was casting metal type in the 1450s, he had to account for ink spread—the way liquid ink squishes outward when pressed onto paper, thickening strokes and filling in tight joints. So he cut his letter punches with joints that looked too open, too loose, knowing the ink would fill them in during printing. Then phototypesetting arrived in the 1960s and suddenly joints that worked perfectly in metal looked anemic on film because there was no ink spread to compensate for. Designers had to recalibrate everything. Now we’re in the digital era, where a typeface might render on a 4K monitor, a cheap LCD, a phone screen, and in print—each context changes how joints behave optically. Type designer Nina Stössinger told Eye Magazine she now designs “joint families”—slightly different connection geometries for different rendering environments. The capital ‘A’ you see on your screen might have a different apex joint than the “same” letter in a PDF, adjusted by fractions of a unit to maintain structural integrity across contexts.
The weirdest part? You’ve been reading these joints your entire life and probably never consciously noticed one. That’s the point. A well-designed typographic joint is like a good joke edit in a film—invisible until it’s broken, then suddenly all you can see. I definitely can’t look at lowercase ‘a’s the same way anymore.
