Laser-etching keycapsLaser-etching keycaps for a cyberdeck. Posted by Tinfoil_Haberdashery.
The keycap is an opaque PBT one. The UV laser seems to denature the pigment and/or ablate the surface in a way that makes gray marks.
The laser used was a SFDC SFX-UV and it is a 3W engraving laser. (A galvo head UV fiber laser.)
Published on Thu 20th May 2021. Featured in KBD #27 (source).
Some inspiration for you: these strange 3D structures by @taneyats are actual keycaps.