How to define keycaps?
Keycaps are applied on full-travel keyboards. Now, most keycaps are generally surface-printed, they can be double-shot molded, laser printing, sublimation printing, engraved, or they can be made of transparent material with printed paper inserts.
What’s a full-travel keyboard?
Currently, a full-travel keyboard refers to a keyboard with full-travel distance, about 4mm. Full-travel keyboards are the most common keyboards today. There are one-piece plastic keytop or switch plungers. Full-travel distance can prevent accidental key presses in some ways.
Each row of keycaps forms the keyboard profile. When we talk about a “low-profile” or “high-profile” keyboard, we are talking about the keyboard height, which is determined by the height of the switches and the height of the keycaps.
A curved keyboard is placed on a curved plane, and all keycaps are in the same profile. But, the keycaps of a sculptured keyboard have different profiles from the top to the bottom in each row. Today, flat and chiclet keyboards are more commonly used in the laptop keyboards. As for the staircase profile keyboards, all the keycaps have the same profile and are arranged in a stepped profile. Check the image above⇑
Legend & Position
What is a legend? A legend is an inscription on a keycap. All the alphabets and symbols on the keycaps are legends. As for the position of legends, nowadays, in general, there are two main positions: centered and side-printing. See the examples below⇓
Centered: the legend is printed on the center of the keycap.
Side-printing: or front-printing means that the legend is printed on the front side of the keycap.
Normally, the standard keyboards have four-row profiles: function row, number row, alphanumeric rows, and spacebar row.
| Row | QWERTY |
| Function row | Esc, F1-F12 |
| Number row | 1-12 |
| Tab row | Tab, Q-P |
| Home row | Caps, A-L |
| Bottom row | Shift, Z-M |
| Spacebar row | Ctrl, space bar |
What is double-shot injection molding?
Double shot molding also refers to as two-shot molding. It is the manufacturing process. Two different materials are used to produce complicated molded parts, molding plastic around a performed metal or plastic insert.
One material is injected into a mold to make the initial piece of the product, and the second injection of other material is compatible with the first injection molded piece.
Double shot keycaps are de facto standard in the 1970s and the 1980s. Double shot molding is a great process for complex, multi-materials, and multi-colored plastic products. Double shot molding can enhance product quality. Today some well-qualified keyboards are still used double-shot keycaps.
Double-shot Keycap in ABS
Materials
Now the most common and popular materials are ABS and PST. Each one has its pros and cons. They are applied in various keycaps according to their characteristics. Of course, there are many other types of materials. Let know them one by one.
ABS
Most keycaps are made of ABS. ABS is short for “Acrylonitrile Butadiene Styrene”. Acrylonitrile makes it harder; Butadiene makes it flexible and less brittle. Most double-shot keycaps are adopted with ABS materials. That’s because those other plastics shrink too much during the molding process.
Pros
- ABS materials will gradually turn yellow from exposure to ultraviolet light over time.
- Shiny (depending on the caps)
- Easily get smudgy (depending on the quality)
- Usually thinner
Cons
- Cheaper
- Smooth
PBT
PBT is short for “polybutylene terephthalate”. PBT is one of the hardest, most durable materials for keycaps. Its properties make it harder to mould. PBT won’t turn yellow from exposure to ultraviolet light.
Pros
- Textured
- Matte or semi-matte
- Usually cannot smudge
- Generally thicker
Cons
- More expensive
PC
PC stands for polycarbonate, which is used for clear and transparent keycaps. PC is more impact-resistant and doesn’t turn yellow. Sometimes PC is blended into ABS to be ABS-PC.
POM
POM is short for polyoxymethylene that is a thermoplastic. It’s hard and durable. It has low friction, being slippery to the touch. It is denser than PBT and ABS keycaps.
Keycap printing
How is the ledge printed on the keycaps? It comes to keycap printing. As technology develops, keycap printing is improving always. You are welcome to add more advanced technologies.
Pad printing
Pad printing is the most popular method of keycap printing. Pad printed legends are a lack of durability.
Laser marking
Laser marking uses a laser beam to mark the legends onto the keycaps. Various ways can be altered the plastic color with a laser beam. It has difficulty in achieving clean coverage of solid fill areas. Here introduce two common methods:
Charring
Charring or etching means that a laser heats the plastic charring to a darker shade. Because of the natural color of the charred plastic, traditional charred keycaps have pale grey or dark beige legends.
Foaming
It’s a considerately new technique. Foaming uses a laser to create some small, hard bubbles on the surface. It creates a nearly white legend on black plastic.
Engraving
Engraving is widely used for custom products, cutting custom name badges. The writing is engraved mechanically in paint grooves.
Dye sublimation
Dye sublimation is popularly used in the 1980s and the 1990s. It’s a process where heat has impregnated a material with a dye. Instead of forming a painting layer on the top of the plastic, dye sublimation combine the dye and the plastic together. Because its characteristic, dye sublimation lasts longer and won’t easily wear out like laser printing.
However, there is one disadvantage of dye sublimation. Dye sublimation requires the dye must be darker than the plastic material. Today, it’s mostly used for white, grey or colored keycaps.
Keycap mount
We have discussed the keycap material, keycap printing, keycap legend, and keycap molding. This part will discuss keycap mounts. Most mechanical keyboard DIY buff could be very familiar with keycap mount. A keycap mount is an interface between a keycap and a switch. If you’d like to change the keycaps of a mechanical keyboard, you must find the correct keycap mounts that match the switches. That’s because some famous mount types are standardized by switch and keycap manufacturers.
Check the most notable switch mounts below⇓
| Type | Cherry MX mount | Alps mount |
| Image |  |
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