The Voyager's keycaps are precision-injected (doubleshot) out of PBT plastic. This means the letters and numbers are baked into the key using milky, translucent plastic. They will never wear out, and the Voyager's lights shine through them beautifully.
The keycaps are beautifully textured. Not too rough, but not smooth and slippery either. Even the tactile nubs are custom-placed to their exact specifications. In factory tests, they felt that most Choc keycaps placed their tactile nubs too low, so they moved them up to where you'll actually be able to feel them while typing.
When it came time to make them, they just had to go with Tai-Hao, who is One of the world's leading keycap manufacturers, Tai-Hao has been partnering with ZSA for years.