Does Thick ABS perform the same as Thick PBT?

Learning and discussion Keycaps
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Hi everyone who is reading this thread.

I have seen that GMK keycaps seem to use ABS instead of PBT, after researching, it turns out that GMK keycaps use Thick ABS which people say is ‘‘high quality’’.

But I am yet to be sure if this ‘‘Thick ABS’’ would perform like Thick PBT. I mean I’m quite convinced this ‘‘Thick ABS’’ is ‘‘high quality’’ since most cheap keycaps that use ABS use ‘‘Thin ABS’’ which I am sure is bad and could cause shiny and oily keycaps. But just for confirmation, I’m asking this since for me, ABS seems like the word for bad, maybe because I often hear that ABS is thinner then PBT.

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The short answer is no, they will not perform the same.

The beginning of the longer answer is that one isn’t necessarily better than the other overall, but one may be better for your preferences or use case.

Rambly details about why it's preference

ABS and PBT are structurally different types of plastic, and keycaps come in a whole range of thicknesses in both materials - and a few others, too. Blends are also common these days.

When it comes to keycaps, the biggest objective advantage to PBT is that resistance to shine. It also tends to sound and feel different than equivalently shaped ABS, but that’s more subjective. An objective disadvantage to PBT as a material is its tendency to warp when cooling after being molded; you’re more likely to run into twisted or bent keycaps in PBT than in ABS.

Blended PBT sets (including ones whose marketing may not mention they are blended) resist shine better than ABS, but not as well as pure PBT - over time they will shine much like an ABS set. Blends mostly show up in budget doubleshot sets, or in general doubleshot sets that claim to be PBT without much detail given.

Some folks prefer the sound and feel of PBT, some prefer the sound and feel of ABS. For me, it depends on the profile and the other parts they are paired with. For daily use, I tend to prefer PBT because I do have oily skin that quickly shines ABS sets - but I enjoy using those ABS sets more because of the sound and feel in most cases.

“Quality” with keycaps really comes from the care taken in manufacturing and possibly the purity of the material - but thickness on its own isn’t necessarily good or bad. I have some thick keycaps I’d call poor quality because they have crooked letters and warped stems (YMD laser-etched Cherry profile). I likewise have some thin ones I’d call high quality because they are consistent with crisp letters (Signature Plastics double-shot DSA profile).

I think thin keycaps pair well with light or otherwise subtle switches; they let you feel more of a light tactile bump, or experience more of a given plastic’s texture. Likewise I think thick keycaps pair well with heavy or otherwise more intense switches like strong tactiles - and that’s just my preference.

TL;DR: If aesthetic durability / resistance to shine is a key value for your caps, I do suggest sticking with pure PBT. Some of those sets will still show light surface scratches (easier to see on darker colors and fine textures - MT3 Black Speech, for example), but most pure PBT sets I have don’t show any signs of wear at all (any given NK_ Cherry set, for example).

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Thanks for that really informative information! But why would GMK use ABS on their keycaps?

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@TechKid Good questions.

A lot of keycaps are ABS. It’s easier to doubleshot, which means molding the legends, and usually the novelty art, into the cap itself from a separate color of plastic. That enables any color combination and extremely crisp legends. Legends made using dye sublimation on PBT caps tend to be softer, though they can come close on good quality keys.

It is also difficult with PBT to make quality dark caps with light legends. The process used is called reverse dye-sublimation, in which the legend area is masked out and the entire keycap dyed except the masked part. Getting the colors right this way can be difficult, especially if you have a base keycap that is anything other than white. Think about trying to dye a lavender base keycap black with lavender legends showing through. It’s going to be difficult to get a true black.

As Deadeye said, you can also get more warping on PBT at the factory (though you can possibly warp ABS with a hairdryer, which should be too low a temp for PBT). This is especially true of reverse dye subbed caps, especially long ones like spacebars. My understanding is the dye sub process uses high heat, and dying all sides of the cap takes longer exposure to heat, increasing the chance to warp.

I’ll also note that ABS sounds different, and different brands also sound different even when dealing nominally with the same material.

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So would getting ABS keycaps (Cheap or expensive ones), be alright? Or would going PBT which is more expensive better?

But your saying about ‘‘It is also difficult with PBT to make quality dark caps with light legends’’ I could agree.

Because I saw that Keychron has a keycap set called ‘‘Developer Keycap Set’’ which is a dark keycap with purple legends and it uses PBT Dye-sub, and I wondered why it was a bit expensive and has Dye-sub instead of doubleshot. And after reading your reply, I start to know why it’s more expensive, it’s obviously because of the difficulty of making a dark keycap with purple legends.

Thanks for the informative information.

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ABS keycaps will most likely start to become shiny, specially with cheap Sets that use cheaper materials and blends. That’s just how the material behaves, sadly.
PBT is way more resistant to it and it will take a lot longer as it’s more durable, but it’s not really possible to get colors as deep and dark as you would get with ABS. Doesn’t matter if Dye-Sub or Double-Shot, it’s just a characteristic of the Material itself.
Personally i would go for PBT over ABS because i just hate shiny keycaps and how they feel, but people swear by the sound and feel of ABS. ABS being usually higher in pitch but more muted than PBT. But it’s all preference, of course.

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It also depends on the keycap profile, which affects weight. For example Signature Plastics SA keycaps are heavy, despite being made of ABS (double shot, very crisp, expensive too…) and will affect the feeling and sound a lot. KAT keycaps are made of PBT and have a very refined sound, in good part because they are quite tall and thick too, and the internal shape has been made to optimize sound propagation. MT3 is another interesting example, additionally because you can find them in ABS or PBT and they do affect the sound a lot (in similar ways, but not exactly like SA).

SP SA caps are shiny by default so they wont pick up shine like textured tops (Cherry or DSA for example).

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Apparently yes, ABS can shine.

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Thanks for that information.

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A few pedantic notes:

GMK’s traditional CYL profile caps are ABS. (CYL is the name they now use for Cherry profile, because it is cylindrical.) GMK’s new MTNU spherical profile is doubleshot PBT.

Like Drop MT3, Signature Plastics can make DSA in either doubleshot ABS or dyesub PBT. (I can’t remember if they do that for other profiles.) SP SA is available in a couple of textured finishes, as well as shiny.

PBT is apparently more porous than ABS, which is necessary for dyesub to work. It’s harder than ABS, so all otger things being equal one would expect it to be higher pitched, but other things are usually not equal.

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A related question, why is the keycap market seemingly dominated by ABS and PBT? Switches are made from a larger variety of plastics, like PC, POM, nylon, etc. Are these other materials not so suitable for keycaps?

I have seen some alternative material keycaps offered for sale, like ceramic, resins, POM, PC, and various metals and woods, but these are all considerably less common than ABS and PBT.

Has anyone tried any of these other materials? How do those compare against ABS and PBT?

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There are good and bad keycaps out there using either material. You’re totally fine getting either one, if you’re okay with the ABS shining (becoming more smooth where you touch it over time). It’s just a personal choice.

PBT sets are usually cheaper, so you may want to double check what people think specifically about the more expensive PBT set you’re considering.

I haven’t tried the Keychron sets. I assume they are fine but not great, though maybe someone else has actual experience.

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I’ve tried a couple of the less common keycap materials, namely wood and ceramic.

Wood:

The wood caps I have are from KBDfans, and are made using plastic stem inserts and some kind of lacquer coating. The caps are gorgeous, but not really fit for use IMO - that coating wears-out very quickly under skin oils, making for an inconsistent appearance. The coating feels like what it is; which is to say not something really meant as a point of interaction for human skin. A bit tacky.

I have a recording, though it’s not all that helpful being on dampened switches:

I can tell you they sound deeper than any plastic cap I’ve tried, but not as deep as ceramic. If memory serves, they aren’t heavy enough to significantly alter switch behavior like novelty metal caps are.

This particular wooden set is a beautiful display piece but I really can’t recommend it with the surface treatment. I’ve seen individual caps on Etsy where the wood itself is a durable type or treated for longevity (ie simply oiled and stained) instead of just being coated with what amounts to dissoluble plastic.

Ceramic:

Not the best recording either, but on more standard switches - and at least gives the impression of how D E E P these can sound:

Copypasta from a recent desk-today post; half-and-half about the Cerakeys and the Aurora I put them on:

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Generally, everyone here has answered the question, but basically, there’s good sets of both types. Personally here are some caps I enjoy, by material:

ABS plastic: thick GMK doubleshot keycaps, thin SP DCS doubleshot keycaps, (rarely, but occasionally other SP SA/DSS/DSA doubleshot keycaps)

PBT plastic: thick Hammer CRP dye-sub keycaps, thick Original Cherry dye-sub keycaps, thick EnjoyPBT dye-sub or blank keycaps, thin OEM Topre dye-sub or blank keycaps, (occasionally SP DCS dye-sub keycaps).

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As Lightning said the question has been answered but I Just want to emphasize that thickness does not equate to quality all of the time. The quality of the material used in the first place would probably be the biggest factor IMO. While it’s not something we think about a lot, there is different grades of every type of plastic. So there are thin ABS/PBT/etc. keycaps that are very high quality & thick ABS/PBT/etc. keycaps that are fairly low quality. Also the production itself has a hand in quality too. You can use the highest grade plastics out there, but if the production methods are lacking the resulting keycaps would not be considered high quality.

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Ah ok.

I just knew that GMK has Doubleshot PBT. Thought they only had Doubleshot ABS.

What do you mean by this though ‘‘so all otger things being equal one would expect it to be higher pitched, but other things are usually not equal.’’

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SP SA exists in both ABS double shot and PBT dye sub (one set only so far). Both are of extremely good quality.

Is there any material science that backs this claim ? From what I can recall, PBT being more appropriate for the dye sub process is because of temperatures involved. Scientific papers I can find mention porous compounds of PBT+PEG for medical use but that’s a different material altogether. Also the surface texture of keycaps is completely determined by the mold.

PBT material density is higher (about 30% more than ABS) which leads to a different sound propagation profile to start with, even if they mold is strictly identical. In practice, with equal keycap profile and thickness, a PBT version will absorb more sound waves than ABS. This will lead to a bigger difference on small profile keycaps such as Cherry or DSA profiles, while SA for example is mostly characterized by sound wave reflections under the keycap itself.

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Yeah Cherry did make POM keycaps back then, you might still find old school keyboards with these, they are quite interesting sound wise, but many people dislike their very slippery, almost oily surface.

Wood keycaps require a lot of very fine manufacturing. You can find a lot of them on Etsy and such, but you’ll find that the price is reflecting that manufacturing issue.

Metal keycaps do exist and are sold by a few outlets (Gateron themselves, then https://awekeys.com/ or if you want full sets and extended compatibility https://metalkeyboards.no/ ) and are really expensive too when well made as each keycap is CNC milled. They sound suprisingly deep (I have a metalkeyboards set).

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The keycap shine thing is both bad and good, on some colors like white, it can become good, but black colors? No.

So again, it will depend, but though I will probably stick with PBT, either Dye-sub or double-shot. I like the color of PBT, and since it would last longer before it shines or even never shine, I guess I will have a sweet new looking keycap set even after I use it for years! Well, that’s if I clean it.

The Keychron sets look convincing, given the higher price. I might get Keychron keycaps, specifically their PBT Double-shot ones, but it seems like Akko is better and cheaper, so I’ll get Akko keycaps.

Also, is PBT Dye-sub washable? And will it last like or almost like Double-shot PBT?

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@LightningXI
Wow, it seems that dye-sub is more common on PBT, I mean I can’t complain since as double-shotting a PBT material keycap is more difficult than on ABS.

I always see Dye-sub as a bad thing, but is it though? I see that double-shot is much stronger, well that’s what it says from articles or other thing’s I read.

@Surefoot
Wow, it seems a lot of people in the community is smart.

Though, what is SP SA? Would you mind telling me all the keycap profiles? Including uncommon ones, not just Cherry, SA, and other common ones.

‘’ PBT being more appropriate for the dye sub process is because of temperatures involved.‘’
I would agree, since Dye-Sub uses high heat, PBT is more common as PBT has a higher temperature durability before warping than ABS.

Though I do not know anything about material science. But i’ll wait for @fanf reply, so I might learn some more.

@Rob27shred
Thanks for that information.

I can agree on the statement about material quality, material quality is different on every keycap, it can’t exactly be the same quality grade, so quality on a material can be good, bad, excellent, or unviable. And yes, thickness and thinness depends on the material quality.

I also agree on your statement about production method quality, if the production methods are bad, it could result in a bad keycap, otherwise, if the production methods are good, it can result in a quality good keycap.

(Sorry if I kind of copied your statement, I just wanted to add a few details, and maybe not make you feel that I didn’t reply to you

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