How to Cast Embedded Keycaps

Ever since I started in this hobby, I wanted to create interesting keycaps that have a relatively flat surface. Any prominent texture would distract me from typing. I couldn’t find the industry term so I’m calling these types of keycaps “embedded keycaps”. Think Zen Pond from jellykeys versus Jade Empire from Keyforge.

After feeling confident from casting single color keys, I experimented with making more advanced molds to make embedded keycaps. I thought about literally embedding objects (which you can do to create glitter or gold foil keycaps), but I wasn’t sure how to embed more intricate objects and have them not float and move during the curing process. I decided to go with advanced molds for now and I’ll make a separate post on mold design.

It took a lot of iterations of mold design and casting technique before I created anything resembling an embedded key. I was surprised by the difficulty but it was probably my lack of intuition for physical crafts. Below is my current process.

Three Day Process

This is a three day process to create embedded keycaps using three different mold pieces. While I used molds with simple geometric shapes, the same process can be applied to more detailed molds. The process takes many days because I wait approximately 24 hours for resin to cure between the steps.

First Day – Cast the Details

I cast the details of a two-part mold (such as the hemisphere or stars) as well as the stem mount. I wiggle the stem to release any air bubbles trapped in the mount. Casting the stem on the first day (instead of the second day) avoids creating air traps.

Second Day – Cast the Bottom

The second day is for casting the bottom of the keycap that surrounds the switch’s upper housing. I fill the mold with colored resin and press the two halves together. I need to carefully clean out the escape holes to help prevent air holes forming along the bottom ridge of the keycap.

Third Day – Final Cast

The third day is for combining the bottom pieces with a clear top for the final cast. I use molds with the desired surface profile in this step. I spray the molds with mold release, fill them with clear resin, and then inlay the bottoms from the previous day. The mold release makes the keycaps shiny.

That’s it! That’s my process. I’m sure I’ll change it as I learn more. If you’re just getting started, check out intro tutorials at http://artisanalliance.mx/ and my list of materials.