How to choose a keycap set for a split, ortholinear, or columnar keyboard.
Ergo boards (split, ortholinear, columnar) rearrange the keyboard to fit your hands instead of the other way around. That changes which keycaps actually work: layouts have odd key sizes, rotated thumb clusters, and columns staggered by finger length rather than by row. This guide walks through choosing a set that covers your board and feels right under an ergo layout.
Start with the switch, because it decides everything downstream. The stem under your switch is what the keycap clips onto, and the main families don't interchange. Most ergo boards run Choc (low profile, light, travel-friendly) or MX (standard, taller). Topre and EC barely come up here: to this day there are almost no ergo boards built around them, so it's rarely something you'll need to plan for.
One catch with low profile: "low profile" doesn't automatically mean Choc. Plenty of low profile switches are Choc v2, or come from other brands like Gateron with their own stem shape, so it's worth knowing exactly what's under your fingers before you order. Stem aside, Choc and MX keycaps also usually come in different sizes, because the two switch families use different spacing, so a cap built for one won't line up on the other. If you're not sure what you've got, read Choc vs MX vs Topre first: it covers stems and spacing, and it's a thirty-second check that saves a wrong order.
Honestly, profile is mostly down to preference and how comfortable you are with each one. There's no single right answer, so treat the points below as nudges rather than rules.
Ergo boards are usually columnar staggered, meaning the columns step up and down to match your finger lengths. That's why a lot of people reach for a cylindrical profile, where the top of each key is scooped along one axis like a shallow valley, shaped to guide your fingertip as it travels up and down the column. Others prefer a spherical top, dished in from every side like a small bowl, which some find more comfortable and which helps your finger settle in the centre of the key for typing accuracy. Both are valid; it comes down to what your fingers like.
Height works the same way. Low profile is the usual pick for ergo because it keeps your hands relaxed when the board is tented or split, but plenty of people are simply more comfortable on a taller profile, or just raise their desk or keyboard to suit.
To put names to it, here's where our profiles land:
If you're not sure where to start, go uniform and low profile, get used to it, then branch out and try other shapes once you have something to compare against.
Most ergo boards are mainly 1u keys, with a few larger caps for the thumb cluster, and that's exactly how we build most of our kits. So coverage usually isn't the headache it can be on a standard board. Still, count the keys on your board and check them against the kit contents listed on the product page before you buy, since odd thumb keys and homing caps vary from layout to layout.
Legends are the looser part. Ergo boards tend to be highly customizable and built for touch typing, so your fingers know the layout better than your eyes do. We'd recommend keeping some tolerance for approximate legend matching: a set that's close is usually fine when you're rarely looking down. If you want it exact, you can always order custom keycaps printed for your layout.
A few boards come up often enough that it's worth flagging what to watch for:
Filter the catalog by switch type and profile to match your layout.