How are artisan keycaps made?
Every keycap that is casted originates from a handmade clay sculpt, crafted using traditional methods. Sculpting on a 20x20mm canvas is a very intricate task; a finished sculpt can take up to 40 hours of work to complete.
To make a mold, silicone rubber is poured on top of the sculpt which when hardened makes a negative hole in the exact shape of the sculpt. This mold is then used to cast the finished keycaps.
Every keycap is casted by hand with the assistance of a pressure pot to keep bubbles from building up inside the cap. The simplest type of casts are called "singleshots", meaning that only one pour of resin was used to cast the keycap. This results in a finished keycap that has only one color.
While this is usually the simplest way to cast, there are a lot of different materials and methods that can be used for different effects that are far from easy. For example, the grey "Sparkey" in the picture is casted using 30% aluminium powder and 70% resin, which gives it the color, weight and feel of the metal, while still keeping the properties of the resin.
Multishot keycaps are, as the name might suggest, caps that take multiple shots of resin to complete. To achieve multiple colors in one cast, resin of different colors are "painted" into the inside of the mold, which makes the color an actuall part the finished cap.
This does not only ensure a very clean look of the colors, but also makes them impossible to rub off like paint would. This is the hardest and most time-consuming type of casting; for each extra color to be added, another batch of resin needs to be mixed, and also cured afterwards. In other words, you could essentially make 4 singleshot caps in the same time as one 4-colored multishot.