The Ars Technica guide to keyboards: Mechanical, membrane, and buckling springs

The Ars Technica guide to keyboards: Mechanical, membrane, and buckling springs
Aurich Lawson

Your keyboard is the thread that connects you to your computer. The way a keyboard feels—from the sensations of each key pressing down and resetting to the build of the board’s chassis—has a direct impact on your typing experience, affecting accuracy, speed, and fatigue.

We’ve dug into the joys of quality keyboards and the thrills of customization at Ars Technica before. But what really makes one type of keyboard feel better than another? People say membrane keyboards feel mushy, but why? And what about keyboards with cult-like followings? What makes decades-old IBM keyboards or expensive Topres so special?

In this guide, we’ll look at how some of the most popular keyboard categories work and how their differences impact typing feel.

Mechanical keyboards

Many people consider mechanical keyboards to be the king of keyboards. Mechanical keyboards are generally very tactile, as their keys offer distinct feedback with each press. Customization options that impact feel, appearance, and sound mean that mechanical keyboards are also great for users who want to tweak individual parts to get the precise feel they’re looking for.

So why do they feel so good to type on? Let’s take a look.

The switch under each mechanical keyboard key has more components, moving parts, and travel compared to a membrane keyboard, making button presses feel more substantial. Pressing a mechanical switch sends its plastic stem downward, while the spring provides resistance. As the plastic stem moves downward, it allows the switch’s two metal leaves to make physical contact, closing a circuit and sending a signal to the keyboard’s printed circuit board, or PCB. (Check out this article from Kinetic Labs for an overview of the basics of mechanical keyboard PCBs). Depending on the stem’s design, the keypress might go down smoothly (in linear switches), with a discernible bump along the way (tactile switches), or with a bump and a click sound (clicky switches).

When the button is released, the spring creates feedback while the key resets, during which the plastic slider comes back up vertically and separates the switch’s metal leaves again.

That’s how mechanical switches usually work, but some modern examples tweak that formula, such as optical switches (which actuate depending on if the switch’s stem travels through a light beam) and Hall effect switches. Additionally, Varmilo produces switches that work like a standard mechanical switch, but instead of actuating via metal contact points touching, the metal points just come very close to each other during keystrokes. This changes the electrostatic capacitance of the electric field between the two contacts, resulting in input (these electrostatic capacitive switches work differently from Topres, which we’ll get into later).

Varmilo's depiction of a standard mechanical switch actuating (left) versus one of its electrostatic capacitive switches actuating (right).
Enlarge / Varmilo’s depiction of a standard mechanical switch actuating (left) versus one of its electrostatic capacitive switches actuating (right).

Mechanical keyboards also provide customization options that make it easier to fine-tune the typing experience. Mechanical keyboard customization options include switch type, keycap sizes, shapes, and material; different types of cases, gaskets, and plate mounting styles; and applications of foam, lube, and stabilizers. Conventional membrane keyboards don’t allow for this kind of personalization.

Some people also find that the feedback and travel of mechanical keys help with the physical discomfort associated with frequent typing. And while companies often market the short key travel of scissor switches as a way to type faster, mechanical switches can also help with speed and accuracy because of their distinct keys and tactility. (We’ll look at scissor switch keyboards in a bit.) Further, some mechanical switches require little force and/or travel to actuate, which can also help with speed and the amount of energy exerted while typing.

Membrane keyboards

Membrane keyboards are more common than mechanical ones, even though most keyboard aficionados will tell you that membrane boards are inferior. I’d certainly take the feedback-heavy keys of a mechanical keyboard over nearly every membrane keyboard. But the membrane keyboard category also includes beloved designs, such as retro IBM keyboards.

We’ll get to some of these enthusiast membrane designs later, but let’s start with how membrane keyboards generally work.

Instead of using a hard PCB like mechanical keyboards do, membrane keyboards work with thin, plastic membrane sheets. Today’s examples typically have three membrane sheets, with conductive traces on the bottom of the top layer and the top of the bottom layer. The membrane sheet in the middle serves as a spacer and has a hole for each of the keys. Push a part of the top membrane down and it goes through the middle membrane’s hole, touching the bottom membrane layer and transferring current. Because the keys are nearly flat, they don’t provide as much tactile feedback as mechanical keys.

A membrane keyboard's three membrane sheets.
Enlarge / A membrane keyboard’s three membrane sheets.

Membrane sheets are about half as thick as the PCBs in mechanical keyboards. This often results in keyboards that are cheaper to make and less rigid, with the potential to be very thin. The latter is handy for use in laptops and portable keyboards.

Further dictating what a membrane keyboard feels like are the other components involved in keystrokes.

Rubber dome keyboards

Rubber domes are the most common type of membrane keyboard. As the name suggests, each key uses a rubber dome that collapses when pressed, making contact with the keyboard’s top membrane sheet and so on.

The rubber domes deliver some feedback when pressed, and rubber dome keyboard keys can have as much travel as mechanical keyboard keys. But a soft, thin piece of rubber offers less resistance, tactility, and sound than mechanical switches do.

Rubber domes come in six different styles. Not all are common among keyboards; some are typically adopted for other use cases, like phones or calculators. The type of dome used has implications for the feel (and therefore force curve) of keypresses, including key travel length and how much force registers as an input.

A look at different types of rubber domes, via N&H Technology GmbH.
Enlarge / A look at different types of rubber domes, via N&H Technology GmbH.

Scissor switch keyboards

That brings us to a specific and common type of rubber dome membrane keyboard: the scissor switch. Scissor switches are like rubber dome keys, but they add a cross-arm mechanism around each dome.

Scissor switches generally have shorter travel than non-scissor-switch membrane keyboards that use rubber domes (typically around 1 mm–2.5 mm, though I’ve seen some with slightly more travel). They’re generally used in situations where low-profile switches are desirable, like in thin-and-light laptops or inexpensive keyboards that companies market as enabling fast typing. Some people find the short travel and mushiness of scissor switch keyboards lead to typos or fatigue, though.

I reached out to peripherals company Logitech for an explanation of why scissor switches are shallower. Sylvain Sauvage, head of UX design, and Art O’Gnimh, GM and VP of personal workspace, said in a shared response that the rubber domes used for scissor switches are thinner and shorter than those used for standard rubber dome switches and that “the scissor structure stabilizes the key and allows for a more direct and shallower action to register a keystroke.”

Compared to standard rubber dome keyboards, scissor keyboards are often characterized by a “sharper feel and less wobble” and by “being more precise” since “actuation happens faster due to a shorter travel,” the Logitech execs said.

Scissor switch keys require less force to register a keypress than standard rubber dome keyboards because the latter has longer travel, resulting in higher resistance, Sauvage and O’Gnim said. Comparably thinner domes should also lead to more easily depressed buttons.

Membrane versus mechanical feel

The differences in mechanical and membrane keyboards lead to different typing feels, of course. For example, pressing a key on a membrane keyboard can make you feel that there isn’t anything strong and sturdy underneath the keys—because there isn’t.

If you haven’t had much hands-on experience with mechanical keyboards, though, it may be hard to picture the difference. So I turned to keyboard expert and engineer Jacob Alexander to get some help explaining why membrane keyboards generally feel worse than mechanical ones. Membrane keyboard keypresses simply don’t have the same consistency and reliability, he said, while noting that this can be a flaw of bad mechanical keyboards, too.

“You can have typos and think you made the mistake, but really, you didn’t make the mistake. The keyboard was just designed poorly and gave you the wrong feedback,” Alexander told me.

And while mechanical switches vary in tactility, Alexander argued that the feedback of a mechanical switch, which may include a tactile bump and/or audible click, is much faster, enabling improved typing:

When you have multiple points of feedback, it reinforces [the keypress] so you can move on to the next one. Sometimes you almost know you have a typo before you even look at the screen, and you’re already pressing Backspace … clicky keyboards are even better with that.

We won’t address keyboard sound in this article, but it’s easy to see why membrane keys are quieter than mechanical keys, including those with linear switches marketed as “silent,” which are not actually silent when pressed.

Butterfly keyboards

There was a time when the term “butterfly keyboard” evoked images of the TrackWrite, the keyboard for IBM’s ThinkPad 701C laptop, which opened up like butterfly wings when the laptop’s lid was raised. But the term now generally refers to the keyboards in Apple laptops from 2015 until 2020—and anyone talking about them is likely complaining.

Apple is the most infamous maker of butterfly keyboards, but it’s not the first. Butterfly switches are a type of scissor switch that differs from typical scissor switches because their legs don’t extend below their hinges:

A standard scissor switch (left) and an Apple butterfly switch (right).
Enlarge / A standard scissor switch (left) and an Apple butterfly switch (right).
Apple

The slimness of this switch design appealed to Apple because it makes slender laptops that could always use extra space for components and heat dissipation. But for years, users of MacBook butterfly keyboards complained that the keys were susceptible to frequent breaking, mostly from dust and grime ingress. The problem got so bad that Apple eventually moved its laptops to standard scissor switches and was ordered to pay affected consumers through a class-action settlement.

Topre keyboards

The majority of membrane keyboards you’ll find these days are rubber dome. And the vast majority of rubber dome keyboards are membrane keyboards—but not all. Enter the confusing and beloved Topre switch.

There are other examples of keyboards that use rubber domes but not membrane sheets, but the most relevant for today’s keyboard enthusiast is the pricey Topre. Topre switches are hard to define because they work differently from traditional rubber dome, membrane, or mechanical switches. Each Topre switch has a rubber dome. However, some Topre fans say that calling a keyboard with Topre switches a rubber dome or membrane keyboard (the latter of which would technically be inaccurate) is misleading because they’re not mushy, cheap-feeling, or inexpensive—all characteristics of standard membrane keyboards.

People frequently group Topres with mechanical switches because they have a premium feel and tactility marked by a distinct actuation point. Some enthusiasts argue that Topre switches can feel even more tactile than the best mechanical switches.

Like mechanical keyboards, Topre keyboards use switches that use a spring and a PCB. But unlike mechanical switches, the springs in Topre switches don’t generate much resistance; they’re mostly there to provide some static force to prevent accidental presses. Resistance primarily comes from the switch’s rubber dome. Topre users feel a tactile bump when pressing a key, just like users of tactile and clicky mechanical switches do. However, the feel of the boards is dramatically different, considering the different forces and components used in Topre versus traditional mechanical switches.

Topres register input through a capacitive-sensing PCB rather than via mechanical contact. Of course, electrostatic capacitance-related actuation isn’t the only thing that makes Topres different from most mechanical switches (as mentioned above, some mechanical switches incorporate electrostatic capacitance).

Here’s a more detailed overview of how Topre keyboards function and differ via Topre Corporation’s 1986 patent (PDF):

A keyboard switch is provided with an insulating substrate, a first electrode laid on the insulating substrate, a second electrode formed of a conical coil spring and facing the first electrode, a dielectric disposed on the first electrode, a button positioned on the top portion of the second electrode, and a rubber cap disposed between the button and second electrode, for giving snap feeling to an operator when the button is depressed and the capacitance of the switch exceeds a given value. The capacitance varies with the change in the facing area, which changes substantially in proportion to the depth of depression of the button. The switch is capacitive-coupled for a switching operation and the snap feeling is given to the operator when the capacitance exceeds the given value.

The diagram below highlights Topre switches’ unique construction:

What do Topre keyboards feel like?

So how does all that translate into a typing experience purportedly worth the hefty price that Topre boards carry? In addition to providing distinct feedback, Topres are also coveted for their impressive “thock” sound.

Here’s how a 2020 Gizmodo review of a Topre keyboard describes the feel:

There’s a satisfying little bump as you press a key. It’s not the firm click you feel when typing on most mechanical keyboards. Instead, there’s a distinct roll to it. A feeling of increasing, gentle resistance, and then a smooth release. It’s almost like popping the really big bubbles in packing wrap but without the unpleasantly loud pop at the end.

Former Arsian Jeff Dunn wrote about Topres in a 2023 Engadget keyboard review, saying that “each press requires just enough force and returns just enough even resistance to give my fingers a distinct, bouncy response but not fatigue them over hours of work.”

Look at force curves for Topre switches (examples are available here) and you’ll see that the curves for both de-pressing and releasing change very smoothly and in a wave-like fashion. Traditional mechanical switches tend to have force curves with more uneven bumpiness. This helps explain why people often describe Topre switches as feeling exceptionally smooth.

But as with many cult favorites, Topre switches may be something you have to feel in person to appreciate. Unfortunately, Topre switch samplers aren’t readily available, like samplers from Cherry, Gateron, and other mechanical brands are, and Topre keyboards tend to be restrictively expensive.

Chiclet keyboards

The keys on a chiclet keyboards are small and rectangular, like a piece of Chiclet gum.
Enlarge / The keys on a chiclet keyboards are small and rectangular, like a piece of Chiclet gum.

If someone says they’re using a chiclet keyboard, you can bet it’s a membrane keyboard. These days, people most frequently use the term “chiclet” to refer to the keys of membrane keyboards with small, discrete keycaps that look like Chiclets gum. These keyboards are also sometimes referred to as having island-style keys. A chiclet keyboard uses scissor switches for low-travel buttons, so many laptop keyboards and portable membrane keyboards, like Apple Magic Keyboards, have chiclet keys.

But this idea of chiclet keyboards is an evolution of the vernacular. If you really want to get into the woods (and you’re reading a multi-page article about keyboards, so why not?), the original, true “chiclet keyboards” used a type of technology that’s slightly different from scissor switch or standard membrane keyboards. Old school, traditional chiclet keyboards feature an extra membrane layer (for a total of three) that serves as a buckling mechanism for added tactility:

A diagram of a tradtiional chiclet keyboard.
Enlarge / A diagram of a tradtiional chiclet keyboard.

Examples of true chiclet keyboards include the clackers on the TRS-80 Color Computer, Commodore PET, and, to much chagrin, the IBM PCjr.

Buckling spring keyboards

IBM Model F

Now, to get a little retro. Mechanical switches may be prized among typists today, but before there were mechanical keyboards, there was the IBM Model F and its groundbreaking buckling spring switches. These switches led to the creation of today’s mechanical switches, and you can still find keyboards with buckling spring switches. Other companies made keyboards that used buckling spring technology, but the most influential, well-known, and still relevant board today is IBM’s Model F.

IBM started selling Model F keyboards with buckling spring switches and a capacitive PCB in 1981. The switches have a spring (which is in a barrel instead of on a stem, like the springs in mechanical switches) that bends slightly outward when depressed. The buckling of the spring pushes a flipper connected to the bottom of the spring forward. A hammer resting above two capacitive contacts is pressed forward, creating a change in capacitance. Feedback comes from the buckling spring, and the switches are known to feel heavy to press.

A diagram of a Model F buckling spring switch.
Enlarge / A diagram of a Model F buckling spring switch.

As explained by Deskthority, some Model F XT models had “removable barrel modules that slide into holes on the upper plate, with an additional” peg to help the alignment. The later AT models used the same format, but with an additional notch for alignment rather than a peg, possibly to prevent the piece from interfering with the keyboard’s stabilizer wires.

Additionally, Model F keyboards are praised for durability (since they rely on capacitance instead of physical contacts for actuation) and for having a sharp, firm click sound from the switches’ hammer.

IBM no longer makes these keyboards, but there’s a robust market for used and restored Model Fs, and a company called Model F Labs recreates them for modern computers. Additionally, their legacy continues through today’s mechanical switches.

IBM Model M

IBM followed up the Model F with a less-expensive Model M in 1985. The Model M differs from the Model F by incorporating buckling springs over a membrane sheet instead of using a PCB.

Users often report that Model M keyboards have keys that feel heavier to push than Model F keys. As explained by former Arsian and long-time Model F user Iljitsch Van Beijnum:

The buckling springs also give the keyboard its distinctive feel. The keys offer fairly significant resistance up to a point and then they go all the way down. This is also the moment they activate, so you know exactly when you’ve typed a letter by touch alone, without the need to bottom out the keys.

Like Model F keyboards, you can still find used and restored Model M keyboards for sale. Unicomp also sells modernized versions of the retro boards, with features like USB connectors and Mac support.

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