Back to: Rubber dome keyboard buyer's guide

Frequently asked questions

On this page, you'll find answers to common questions about high-end rubber dome keyboards:

  1. What makes a high-quality rubber dome keyboard?
  2. What are the drawbacks of rubber dome keyboards?
  3. What about Topre?
  4. How do I find good rubber dome keyboards?
  5. Why do you write "mechanical" in quotes?

If you have other questions, you can leave a comment below.


What makes a high-quality rubber dome keyboard?

If you are a mechanical keyboard convertee, you may wonder why anyone in their right mind would want to buy a rubber dome keyboard. First and foremost, we must define our terms clearly. What we usually call a rubber dome keyboard can be fully described by the term "rubber-dome-over-membrane keyboard", using the following definitions:

rubber dome
the piece of rubber, shaped like a dome, that is depressed by the key and, in turn, pushes the key back up
membrane
the thin sheet of plastic, common for all keys, onto which a rubber dome presses, in order to register the key press

The thing to note is that none of these components – neither the rubber dome or the membrane – necessarily produce a poor typing experience. Topre switches, by many regarded to be excellent, use rubber domes, while IBM's old buckling spring switches, widely regarded to be one of the best key switches ever designed, use a membrane.

This page, however, focuses primarily on keyboards that use both rubber domes and a membrane. Because this type of keyboard is by far the most common, there is an enormous variation in quality. This does not, however, mean that all rubber-dome-over-membrane keyboards are bad! Some are, in fact, rather excellent.

Even within the category of rubber-dome-over-membrane keyboards, there are various differences between designs. In the most common (but usually worse) design, the key cap has a long stem underneath it that directly presses on the rubber dome. This design is the cheaper one, which usually, but not categorically, results in lower quality.

In a less common (but far superior) design, the key cap presses instead on a slider, a piece of plastic that slides along the equivalent of guard rails. It is the slider, in turn, that presses on the rubber dome. This results in a much more stable and smooth operation. The design is called "rubber dome with slider" and is what some of the best rubber dome keyboards (if not keyboards in general) use.

High-quality rubber dome keyboards offer a number of benefits over "mechanical" keyboards:

  1. They are generally, but not always, quieter. Even if they make noise, it is not the rather annoying "mechanical" noise produced by most mechanical key switches, but a softer, more pleasant one.

  2. They are tactile in a very specific way. Rubber domes tend to provide a large amount of resistence at first, but almost none afterwards. This results in what can be decribed as a drop, where the key quickly falls to the bottom after overcoming the initial resistence.

  3. They are usually much less expensive.


What are the drawbacks of rubber dome keyboards?

Despite having a lot going for them, even high-quality rubber dome keyboards suffer from one or two drawbacks. Luckily, these drawbacks are more or less important depending on your personal needs. They are, specifically,

  1. the lack of n-key rollover (i.e. not all keys can be pressed at the same time), and
  2. the lack of midway activation (i.e. the key must be bottomed out in order for the key press to be registered).

Some rubber dome keyboards do have n-key rollover, such as the Microsoft Sidewinder X4 (which, however, is otherwise terrible), but most do not. That said, different keyboards support different key combinations, and it is not impossible to find a rubber dome keyboard that works perfectly well for gaming. While the Fujitsu FKB8530 is a poor choice, as W, A and Alt can't be pressed at the same time, the Dell QuietKey RT7D5JTW is quite excellent in my experience.

On the topic of midway activation, it comes down to personal preference. Some people dislike needing to bottom out the keys, but I would estimate that the vast majority of people bottom out when typing in practice. Furthermore, on many rubber domes, such as the Dell QuietKey RT7D5JTW, it is practically impossible not to bottom out, making this a non-issue.


What about Topre?

You may be wondering how these high-quality rubber dome keyboards compare to Topre, which is usually described as a high-quality rubber dome keyboard.

Personally, I think Topre switches are very good and well-designed, and they offer one key benefit over other rubber dome designs (and which none of the keyboards on this page offer), namely that the key press is registered before the key is bottomed out. They also support n-key rollover. Another big benefit is that Topre keyboards are still being produced, unlike many switch designs on this page.

For these reasons, all things considered, Topre keyboards can rightly be considered the best rubber dome keyboards available.

That said, in terms of key feel alone, Topre switches are not the end of the world. While they certainly are good, and I much prefer them over any Cherry MX switch, it is basically a rubber-dome-with-slider design that doesn't really feel much better than other high-quality rubber domes with sliders. If you don't care about n-key rollover or midway activation, then I wouldn't recommend Topre over, for example, the Dell QuietKey RT7D5JTW, which is much less expensive and arguably as nice or even nicer in terms of key feel.


How do I find good rubber dome keyboards?

Even if you don't have physical access to the keyboard, there are other ways to tell apart a high-quality rubber dome keyboard from a cheap one.

The first thing I check is the FCC identifier on the back of the keyboard. If the seller hasn't published a photograph of the back, I usually skip to the next step, unless that also is fruitless, in which case I ask the seller to take a photo of the back.

The following FCC identifiers are interesting:

AQ6-*
NMB domes with sliders

Other FCC identifiers can easily be looked up at fccid.io.

The second thing I do is to search the web for the manufacturer and model number. Sometimes, it can be hard to know which of the numbers printed on the keyboard is the model number, so it is a good idea to try all of them. To narrow the results, I use search filters such as site:geekhack.org, site:deskthority.net, site:telcontar.net and site:reddit.com.

If you're at a total loss, you can ask others on keyboard forums whether they recognize the keyboard. Another option is to simply order the keyboard and see for yourself. Then, you yourself can publish information about the keyboard to the web, letting others know whether it is worth buying. Even a short forum post would be greatly appreciated by others.


Why do you write "mechanical" in quotes?

As noted by many within the online keyboard community, the term mechanical is impossible to clearly define. Most attempts at definitions end up either including undesirable keyboards or excluding desired keyboards. Most obviously, most people try to define mechanical such that rubber dome keyboards are excluded, despite the fact that there are rubber dome keyboards that are much better than so-called "mechanical" keyboards (which is the entire premise of this page).

With the most natural definition of mechanical, all keyboards are mechanical, including those using rubber domes over a membrane. But naturally, as this definition includes all keyboards, it is useless.

Personally, I'd prefer defining mechanical to mean mechanical-feeling. That is, a keyboard is "mechanical" if it feels more "mechanical" than the common cheap rubber dome keyboard. It is basically a synonym for nice-feeling. Such a definition successfully captures what is actually the most important quality of a keyboard: how it feels.

That said, when I, on this page, contrast rubber dome keyboards to "mechanical" keyboards, I am referring to what others call "mechanical" keyboards; hence the quotation marks.

Last updated on 27 Dec 2020.


© 2020 John Ankarström. Up


Comments  •  Submit