Types of Keycaps: Materials, Legends, Mounts, and Kits

Types of keycaps can be classified by material, legend method, switch mount, and kit coverage. These are separate properties: two sets made from the same plastic can use different printing methods and fit different keyboards.

For shape and height, start with keycap profiles explained. This guide covers the other four checks, so a profile name does not have to carry an entire product specification.

Axis 1: material, what the cap is molded from

Almost every keycap you will buy is one of two plastics, with a short tail of specialist materials.

• ABS. Smoother, slightly softer, holds bright colors and sharp doubleshot legends well. Its weakness is shine: the surface polishes where fingers land, developing a gloss over months of use. Higher-end ABS resists this longer than cheap ABS, but every ABS cap gets there eventually.
• PBT. Denser and more heat-resistant, with a drier, slightly textured surface that resists shine far longer. It is harder to mold precisely, so check product-specific molding and long-key straightness rather than treating the material label as a quality certificate.
• POM. Slick, low-friction and self-lubricating, used occasionally for a distinctly smooth surface and a sharper sound.
• Polycarbonate. Transparent or translucent, used for shine-through and RGB-forward sets where light transmission matters more than texture.
• Resin. Cast rather than molded, used for artisan caps, which are individual sculptures rather than sets.

The full comparison is in our PBT vs ABS guide, which also covers the cases where ABS is genuinely the better buy. Material interacts with wall thickness to shape the sound, and the thickness and sound guide explains why thicker caps read deeper.

Axis 2: legend method, how the characters got there

The legend method decides how long the characters survive and, on backlit boards, whether they glow at all. It matters more for durability than the plastic does.

• Doubleshot. Two plastics molded together so the legend is a solid piece of the cap rather than a coating. The character is not a surface ink layer, although the cap can still suffer physical damage. Glorious describes the process as molding the legend layer and the body layer as one part.
• Dye-sublimation. Dye diffused into the plastic under heat. Durable under ordinary use, common on PBT, and limited to legends darker than the cap unless it is reverse dye-sub, which prints the surround and leaves the legend in the base color.
• Pad printing. Ink applied to the finished surface, sometimes with a clear coat. Cheap, sharp when new, and the method most likely to wear away with use.
• Laser etching and laser engraving. These alter the surface rather than simply applying ink. Coatings and infill vary, so read the product description before assuming a particular construction.
• Blank. No legends at all, which sidesteps the whole question and removes a compatibility problem too, although widths, mounts, and the number of keys must still match.

Our legend methods comparison covers the trade-offs in full. If your board is backlit, the legend method and the plastic together decide what actually glows, which is the subject of the shine-through keycaps guide.

Axis 3: stem and mount, whether it physically fits

This is the axis that decides fit, and the one most listings gloss over.

An MX keycap has a cross-shaped socket intended for an MX-compatible switch. Signature Plastics’ family specifications identify mount as a separate property from profile: the socket must match the switch stem.

A cross-shaped appearance is useful evidence of mount type, but does not establish the fit of every switch and cap combination. Check the specific product’s compatibility notes as well as the shape.

The categories worth knowing:

• MX stem. The default. Cherry MX switches and MX-clone switches from other manufacturers.
• MX-compatible alternatives. Check the exact product family and revision, rather than assuming every switch from a brand shares a mount. The clone-brand compatibility guide explains this buying check.
• Low-profile stems. Mounts and clearances vary by switch family. Some have a cross mount and others need a dedicated cap; confirm the exact model.
• Topre and Alps. Separate ecosystems with their own mounts and much smaller aftermarkets.

Getting the stem right is necessary but not sufficient, because a set with correct stems can still leave gaps. That is the next axis.

Axis 4: size and kitting, whether the set covers your board

Keycaps are sized in units, where 1u is one standard alphanumeric key. The spacebar, shifts, enter and the bottom-row modifiers vary in width between boards, and a set that fits a full-size board can leave a 65 percent board with an unusable bottom row.

The parts of a listing to read carefully:

• Base kit versus extension kits. The base kit covers a standard layout. Extension kits add 40s support, ISO, spacebars, novelties or a numpad.
• Bottom-row widths. A 6.25u spacebar board and a 7u spacebar board need different pieces. Split spacebars and split backspaces need their own.
• ANSI versus ISO. ISO enter and the extra key next to left shift are frequently a separate kit.
• Row coverage on sculpted sets. A sculpted set has row-specific caps, so an unusual layout can need rows the base kit does not include.

Our kitting and coverage guide explains the unit system, and the compatibility guide walks the pre-purchase checks in order. Rather than doing it on paper, the kit fit checker takes your layout and the kits a set includes and returns the exact pieces you would be missing.

The special categories

Three product labels describe what is being sold rather than a particular plastic or mount.

Artisans are individually cast resin caps, usually 1u, sold as single sculptures rather than sets. They are bought for the object, not the coverage, and they have their own release culture of raffles and drops, covered in our artisan keycap ecosystem guide.

Novelties are the non-alphanumeric caps in a set: the decorated escape key, the themed enter, the extra modifiers. They are usually a separate kit and often the first thing to sell out.

Colorway kits are the same molds in different color arrangements. The language around base, alphas, modifiers, accents and sublegends is decoded in our colorway terminology guide, and it matters because “does the set include my modifiers in the right color” is a coverage question, not an aesthetic one.

How the axes interact

These four buying checks interact with profile choice. A few relationships are worth carrying:

• Doubleshot pairs naturally with ABS, dye-sub with PBT. Not a rule, but it is what the market mostly produces, so a preference on one axis quietly narrows the other.
• Sculpted profiles make kitting harder. Uniform profiles remove row coverage from the list of things that can go wrong.
• Manufacturer determines availability more than preference does. Which profiles and colorways exist at all is set by a handful of producers, a landscape our GMK vs PBT keycaps guide maps.
• Price tracks the axes unevenly. Where the money genuinely changes the daily experience is the subject of our budget vs premium breakdown, and the best budget PBT sets guide shows what the lower end actually buys.

Specifying a set in one line

Once the axes are separate, a set can be described precisely enough to buy without surprises. A complete specification looks like this: profile, plastic, legend method, stem, and kit coverage for your layout. For example, Cherry profile, PBT, dye-sublimated, MX stem, base kit plus a 7u spacebar.

If a listing does not let you fill in all five, that is the gap to ask about before ordering, not after.

The honest verdict

There is no single list of keycap types, because listings combine several independent properties and often highlight only one. Profile and material decide whether you enjoy the set. Stem and kit coverage decide whether you can use it. Legend method decides whether it still looks right in two years.

Start with coverage, because it is the only one that can make a set unusable, then choose profile for posture, material and legend method for longevity, and colorway last. When the set arrives, our safe installation and removal guide covers seating it without cracking a stem, and cleaning and care covers keeping it looking new.