Variable Fonts — It Was Never About File Size (39c3)

A brief history of typographic misbehavior or intended and unintended uses of variable fonts. Nine years after the introduction of variable fonts, their most exciting uses have little to do with what variable fonts originally were intended for and their original promise of smaller file sizes. The talk looks at how designers turned a pragmatic font format into a field for experimentation — from animated typography and uniwidth button text to pattern fonts and typographic side effects with unintended aesthetics. Using examples from projects such as TypoLabs, Marjoree, Kario (the variable font that’s used as part of the 39C3 visual identity), and Bronco, we’ll explore how variable fonts evolved from efficiency tools into creative systems — and why the most interesting ideas often emerge when technology is used in unintended ways. When the OpenType 1.8 specification introduced variable fonts in 2016, the idea was simple: combine all weights and styles of a font family into one file and save file size and therefore bandwidth. Yet in 2025, variable fonts have become a platform for artistic and technical exploration far beyond their initial goal. This talk follows that transformation from the inside. It starts with a short history of flexible font technologies — Adobe’s Multiple Master and Apple’s TrueType GX formats of the 1990s (I am just mentioning the company names as they were the publishers of these technologies) — and how they failed to become standards. It then shows why variable fonts succeeded: many designers today are more tech savvy and know some basic HTML, CSS and maybe even some JavaScript. And at the same time all major browsers and almost all design apps support variable fonts by now. From there, I present a series of first-hand projects where typography met code: – TypoLabs (2017), whose identity used a custom variable font animating between extremes of weight and width → the variable font family became the (probably forever) unpublished variable font family Denman; – Marjoree (2024), a pair of variable pattern fonts based on hexagonal and pentagonal tilings that explore legibility and repetition; – Kario (2025), a duplex variable font powering the 39C3 identity, with uniwidth weights, optical-size adjustments, and typographic Easter eggs; – and Bronco (2017?), an experiment using the arbitrary-axis model for interpolation to escape the cube-shaped multiple master design space of traditional variable fonts. The talk then moves from history to speculation. Early head-tracking experiments once tried to adjust a variable font’s optical size based on reader position — producing total chaos as text reshaped itself while being read. On the other hand this playful chaos marks the moment when things become truly interesting: connecting a font axis to live data, to mouse movement, to sound, to network input — anything that makes type responsive and alive. That’s the kind of misbehavior I want to talk about — not breaking for the sake of breaking, but using technology the “wrong” way to see what happens. The talk will mix images, a lot of short videos, and a bit of behind-the-scenes insight into font development. It’s about what happens when design tools meet code, and how that intersection keeps typography alive and unpredictable. Link list of variable font experiments: https://www.bronco.varfont.com/ https://www.denman.varfont.com/ https://www.seraphs.varfont.com/ https://marjoree.showmefonts.com/ + 39C3 visual identity Licensed to the public under http://creativecommons.org/licenses/by/4.0 about this event: https://events.ccc.de/congress/2025/hub/event/detail/variable-fonts-it-was-never-about-file-size