Zed is a font superfamily built on four variable design axes and spans more than 500 individual styles. This post attempts to make that vast design space easier to grasp.

Visualising anything in four dimensions is hard. Our brains are used to three-dimensional space; add one more dimension and the idea becomes largely abstract. As a foundry, we usually keep that complexity out of sight, presenting it through simple UI elements instead. Sliders are a familiar way to suggest continuous variation without overwhelming people with options.

Sometimes, though, it’s necessary to show how a family is constructed. For Peter Biľak, the principal designer of the Zed superfamily, that became essential when explaining the type design concept to designers working on other language versions of the Zed type system.

“I made a diagram showing the relationships between design sources, hoping it would clarify the design space for our team—but I think I completely failed. Instead of clarity, it just confuses people,” says Peter. The mind-bending chart doesn’t even show the full complexity of Zed: it includes only 54 primary sources, and omits an additional 36 partial sources needed to produce the fonts.

After trying other approaches, Biľak reached out to fellow designer and programmer Just van Rossum, asking him to help visualise the space. Just’s solution was elegantly simple: show the four axes—weight, width, slant, and roundness—as a flat radial diagram.

Each axis influences the interpolated letterform shown in the centre. The interactive diagram at the top of the page demonstrates the same idea, but with more intermediate steps along each axis. Because every design source is compatible with every other, Zed can interpolate mathematically between the extreme positions of the axes—and anywhere in between.

We invite you to explore the interactive diagram above and get a feel for the Zed superfamily’s design space. Or use the sliders below to jump straight to a final instance, using your own values.