Keycap Basics (What You're Looking At)
Before getting into materials or layouts, it helps to understand the basic terms used to describe keycaps.
Units (u)
Keycap sizes are measured in units.
A standard letter key is 1u. Larger keys are measured as multiples of that:
- 1.25u
- 1.5u
- 2.25u
- etc.
Legends
Legends are the letters, numbers, or icons on a keycap.
Sublegends
Sublegends are secondary markings, often used for:
- Alternative language
- Additional function
Rows (R1-R4)
On most keyboards, each row has a slightly different height and angle.
These are labeled:
- R1 (top row)
- R2
- R3
- R4 (bottom row)
Some profiles include additional rows like R0 or R5.
Stepped Keys
Some keys have a small “step” or indentation, usually on the right side.
The most common example is a stepped Caps Lock.
→ Next: Keycap Profiles
