What Are PolyCaps PBT Keycaps?

Here at Kinetic Labs, we like to have our keycap sets in stock, conceptualized in-house, and designed in collaboration with our favorite artists and content creators. And if you’ve tried to buy keycap sets in stock before, you’ll know that’s quite the feat!

Having in-stock keycaps is far from easy. It requires an upfront investment in what Kinetic Labs believe are good designs, good materials, and good quality processes.

It also means you won’t find keycap sets group buys in the Kinetic Labs shop: you can buy the PolyCaps PBT keycap sets you like, when you like, knowing what you’ll get without having to wait for months, if not years, to receive your keycaps.

In the Kinetic Labs shop, you can find a growing offering of PolyCaps PBT Keycap sets. All keycap sets are made of PBT plastic and they are either manufactured through the double-shot process or the dye-sub process.

The double-shot PolyCaps PBT keycap sets all come with 147 keycaps, a keycap puller, and a carefully designed, exciting packaging experience! The dye-sub PolyCaps PBT keycap sets also come with a keycap puller and a carefully designed, exciting packaging experience—but the number of keycaps per set is not always identical. The number of keycaps varies from set to set for dye-sub keycap sets.

Let me tell you about some of the science behind PolyCaps PBT keycaps and why Kinetic Labs chose that route…

What is PBT and why are PolyCaps keycap sets made of PBT?

PBT or PolyButylene Terephthalate is a semicrystalline, strong, and stiff engineering thermoplastic. It resembles PET (PolyEthylene Terephthalate)—which water bottles and other food-grade packaging are made of, and it’s also part of the polyester family of polymers which is found in textiles and clothes.

PBT plastic is naturally opaque. It’s resistant to UV lights which means it will not yellow over time. It’s resistant to many chemicals like oils, greases, alcohols, solvents—and yes, even sweaty fingers! It’s resistant to moisture, it’s stain-resistant, oh and it’s also resistant to heat—that being said don’t go clean your PBT keycaps in boiling water either.

Hot Tip: speaking of cleaning your keycaps—just soak them in lukewarm water with a drop of dishsoap. And if you have a bit of grimme or dust stuck to them, give them a gentle rubbing with the soft side of a sponge before you rinse them and you’ll be fine. Let your keycaps dry entirely before putting them back on your keyboard (PCBs don’t like water), et voilà!

PBT plastic keycaps are fabricated by injection molding and processed with heats ranging from 230° to 270° Celcius. That makes PBT one of the hardest, most durable plastic to make keycaps out of.

PBT keycaps have a powdery soft texture and a matte finish, they rarely shine over time—I make no promises about your WASD keys—and the nature of PBT makes for thicker, heavier keycaps which—rumor has it—produce a crisp, clear, yet deeper sound when typing.

As you can imagine, PBT was an excellent candidate to make PolyCaps keycap sets for the Kinetic Labs shop. But while PBT plastic can be intricately machined and colored, it is also expensive to produce and difficult to mold. There is nothing cheap about PBT, and it’s not without its issues.

PBT has a tendency to warp and shrink as it cools. It can brittle after extensive use over long periods of time. It’s not the easiest plastic to color. And only a handful of PBT keycap manufacturers can produce Kinetic Labs PolyCaps PBT Keycaps to the standard of quality required.

Hot Tip: PBT can warp or shrink a little as it cools when it’s taken out of its mold. It happens to sometimes find a bit of a bent space bar or a not-so-flat shit key. You can flatten a warped keycap by using heat, a hairdryer or a heat gun (on low) will do the trick. Just remember to be gentle when you press your warm keycap on a flat surface—better to do this a little at a time than to mingle your keycap or snap it once it has cooled.

Did You Know: PET plastic water bottles can be “upcycled” into durable virgin plastic polymers that are ideal for fabricating PBT plastic. Polyamide polymers and polyesters like carpets or clothes can also be broken down into monomers that once re-polymerized transform waste into these quality virgin polymers that PBT is made of.

You can read more about the positive impact that “upcycling” polymers has on the environment in this article: Plastic Compounder's PET Project: Recycling | Machine Design

Making double-shot PBT keycaps

Double-shot is the process of using two layers of PBT plastic injected into a mold to form both keycap and legend into one seamless keycap. The PBT plastics for the color of the keycap and the color of the legend are colored separately and ahead of time. Then the colored PBT plastics are injection-molded into the desired keycap shapes and legends. The finish of double-shot PBT keycaps never fades or strips. The legends never separate or lose their sharpness.

Did You Know: double-shot is the only keycap-making process that allows for RGB lights to pass through the legends on your keycaps, as long as the plastic injected for the legends is not colored.

To make double-shot PBT keycaps, a unique mold must be created for every single keycap. And for the Cherry MX profile, which is the current profile for all PolyCaps PBT keycap sets—that means every keycap per size, per legend, per row. It is the costliest method to fabricate keycaps.

That is why PolyCaps Whale, Octopus, Seal, and Black on White (BoW) all have the exact same layout, the same 147 keycaps per set, and the same compatibilities.

Hot Tip: All double-shot Polycaps PBT keycap sets are compatible with conventional ANSI layouts—including 100%, 75%, 65%, 60%, and Alice layouts. Scroll down on the product page for a complete layout of each set.

Making dye-sub PBT keycaps

Dye-sub or dye sublimation is the process of printing legends, sub legends, and novelties designs on keycaps using a specific type of ink. Sublimation turns solid dye pigments into a gas—without the dye turning liquid, and then that pigmented gas penetrates deep into the plastic hence printing the keycaps. Since the ink pigments never solidify, the legends and novelties designs don’t have any relief. You can’t feel them on the keycaps—only the lovely soft, pillowy, powdery texture of PBT…

On high-quality keycaps, like the Kinetic Labs PolyCaps PBT keycaps, the dye-sub legends will not fade over time or with the erosion of the plastic from extensive use. Because the dye-sub process turns pigments into gas, and gas likes to expend, one of the drawbacks of dye sublimation is that you can sometimes observe a slight fuzz or blur on the legends or novelties designs—this is something you to watch out for in cheaply manufactured keycaps, but not on Kinetic Labs PolyCaps PBT keycaps.

The dye-sublimation process costs less than the double-shot process of making keycaps—meaning that you don’t need to use unique molds for each keycap in your set. The molds can be used over and over according to their row and size, regardless of the legends on the keycaps. But the trick is: keycaps can only be dye-sub printed if the legends or novelties designs’ color is darker than the plastic of the keycap they’re being printed on.

Unless…the reverse dye-sub process is used instead! In order to print a lighter legend or novelty design than the color chosen for the keycap that it’s being printed on, the lighter colored or white PBT keycap is entirely dye-sub printed with dark color(s), except for the legend or novelty design.

Did You Know: dye-sub and reverse dye-sub can only be used on PBT keycaps as sublimation requires a lot of heat and other plastic polymers would melt.

Hot Tip: PolyCaps PBT Corn and PolyCaps PBT Hippo—shoutout to HipyoTech—both have more keycaps than the double-shot PolyCaps PBT sets. They also have novelties and are ANSI and ISO compatible. But Polycaps PBT Corn and Hippo do not have the same layouts nor the same number of keycaps.

PolyCaps PBT keycap sets come with a nice variety of layouts and compatibilities, vibrant colors, crisp legends and novelties designs, the right thickness for a clean and deep-sounding typing experience, and a smooth, comfortable texture—all of this in cool packaging for a premium unboxing experience.

Whether it’s double-shot or dye-sub, with PolyCaps PBT keycaps, Kinetic Labs is committed to offering you great quality keycap sets at an affordable price, with more to come!