This page is talking specifically about keycaps for mechanical keyboards, because, well… there’s not much point talking about any other types distinct from the keyboards they come with as a whole. But most mechanical boards are somewhat standardised, so you can actually swap out keycaps and even, on some boards, the key switches underneath.
If you are going keycap shopping, though, you will quickly realise it’s an absolutely overwhelming endeavour. Here’s what I’ve worked out so far.
Obviously, if you get keycaps, they have to slot onto the keys somehow. This means that the keycaps you get need to be compatible with the switches you have.
The good news is that the majority of mechanical keyboard and associated manufacturers have standardised on Cherry MX-type switches. Cherry itself itsn’t the only manufacturer of these; Gateron is another, and I’ve also heard of Kailh and Outemu/Gaote.
The bad news is that not all mechanical keyboards use (or can be made to use) these kinds of switches. From what I’ve read, “low profile” switches (such as used in the Keychron K3) are generally not compatible. Logitech’s Romer-G switches are also their own, incompatible design, and no market exists currently for custom, aftermarket keycaps for them.
Keycaps can be made out of a few different varieties of plastic. The two biggies are:
- ABS: the cheaper option; generally boards will come with keys made out of this material already. They’re supposed to be “softer” but stronger against potential breakage. Also maybe yellows slightly over time?
- PBT: the slightly more expensive “nicer” stuff. Supposedly feels “sandier” and is harder than ABS, but also more brittle. Also supposed to be “less prone” to yellowing.
This refers to the shape and height of the keys. The primary division, to my mind, is that between “contoured” profiles (where each row of keys has a different height or shape), and “non-contoured” profiles (where every key has a uniform shape, which is good if you need/want to rearrange your keys for a non-QWERTY layout). So, within those categories, the profile options I’m aware of are:
- Contoured profiles
- OEM / Standard Profile: the top of the key is curved as if someone had pressed a cylinder down onto it
- Cherry Profile: similar to OEM/Standard, but the profile is a little lower, and the bottom 2 rows more angular
- SA: a taller profile, where the curve on the top of a key is like if a sphere had been pressed down onto it instead (“spherical” being what the S originally stood for)
- Not contoured
- DSA: shorter than SA; keytops are a little curved (spherically)
- XDA: also shorter than SA; keytops are flatter than DSA, but not totally flat
So if you’re manufacturing keys, how do you get the legends you want on the keys? There are a few possibilities:
- pad printing
- double shot (think of it like this: a thin layer of plastic is poured in a mould, with cut-outs where you want the label to go. then a second thin layer of plastic is poured, filling the gaps but also creating an extra layer on the inside. this makes for a very durable label that can’t just “wear off”)
- laser & infill (use a layer to carve in some grooves, then fill them in – this is what WASD Keyboards does for example)
- dye sublimation (involves the application of dye to an existing keycap at high heat and pressure, so the legend kind of “melds” into the existing plastic of the key. this is what the YMDK set I ordered did)