Keycap Legends: How Letters Get on Keys

The letters, numbers, and symbols on your keycaps are known as legends. The method used to apply these legends to the keycap has a huge impact on their durability, clarity, and feel. A cheap printing method will wear off and fade within months, while a high-quality one will last as long as the keycap itself, even through decades of use.

Understanding the different legend methods will help you evaluate keycap sets and make choices that match your quality expectations and budget.

How the Letters Get on the Keys: A Guide to Legends

Here are the most common methods you'll encounter, from the highest to the lowest quality.

Doubleshot Molding

This is the gold standard for creating durable, high-contrast keycap legends. The process involves molding two separate pieces of plastic together to form the keycap. The legend itself is one piece of plastic, and the outer keycap is molded around it.

How it Works: A mold is made for the legend shape (e.g., the letter 'A'). Plastic of the desired legend color (e.g., white) is injected to create the physical legend. This legend is then placed into a second, larger mold shaped like the keycap body, and a different color of plastic (e.g., black) is injected around it to form the final keycap.
Pros:
- Extreme Durability: The legend is a physical piece of plastic that goes all the way through the keycap body. It is physically impossible for it to ever wear off, chip, or fade.
- Unmatched Sharpness: Creates incredibly sharp, crisp, and high-contrast legends that are pleasing to the eye.
Cons:
- Cost: It is a very expensive and complex manufacturing process requiring precise, high-quality molds, which is why doubleshot keycaps are typically the most expensive.
- Design Limitations: Creating new molds for custom fonts or complex symbols is extremely costly, so manufacturers tend to stick to a limited set of proven legend designs. Multi-color legends are exponentially more complex and expensive.
Commonly Found On: High-end ABS keycap sets (e.g., from GMK, Signature Plastics). It can also be done with PBT, but it is more difficult due to PBT's higher shrink rate during cooling.

Dye-Sublimation (Dye-Sub)

Dye-sublimation is another premium method that produces permanent legends without the high tooling cost of doubleshot molding. Instead of printing ink on top of the plastic, this process uses heat to infuse dye directly into the plastic itself.

How it Works: The legend is printed with special dye onto a transfer paper. The paper is placed on the keycap, and both are placed in a machine where heat and pressure are applied. The dye turns into a gas (sublimates) and permeates the plastic, becoming a permanent part of it as it cools.
Pros:
- Extreme Durability: Because the dye is in the plastic, not on it, it will not wear off.
- Design Flexibility: Allows for very complex, sharp, multi-colored designs and a wide variety of fonts without expensive new molds. You can even print high-resolution images on keycaps with this method.
- Perfectly Smooth Surface: The legend cannot be felt by your fingertip, as it is part of the keycap itself.
Cons:
- Color Limitations: The dye must always be darker than the plastic it is being infused into. This means you cannot print light-colored legends (like white) on dark keycaps (like black).
Commonly Found On: High-end PBT keycap sets, as PBT's high heat resistance makes it ideal for this process.

Reverse Dye-Sublimation

A clever workaround to dye-sub's color limitation. The entire keycap surface except for the legend shape is dyed a darker color. This leaves the original, lighter plastic color visible as the legend. It allows for light legends on dark caps but is more expensive and can sometimes result in slightly softer legend edges.

Pad Printing & Laser Etching (Lower-Tier Methods)

These are more common, lower-cost methods often found on pre-built keyboards and cheaper aftermarket sets.

Pad Printing: A silicone pad is used to press ink onto the top of the keycap. This is a fast and cheap method, but the ink is just a layer on the surface and will wear off over time with use. Often a UV-cured clear coat is applied on top to improve longevity, but it still won't last forever.
Laser Etching: A laser is used to either burn the legend into the plastic (creating a dark gray or black legend) or to ablate a top coat of paint to reveal a translucent layer underneath. This is how most shine-through keycaps for backlit keyboards are made. The legends can be felt and can attract dirt. While durable, they don't offer the clean look of the premium methods.

For a custom build, investing in a high-quality doubleshot or dye-sublimated keycap set is highly recommended for a premium experience that will last as long as your keyboard.

Next, let's find out Where to Buy Keycaps.