Some inspiration for you: these strange 3D structures by @taneyats are actual keycaps.
A set of hollow Cherry MX compatible keycap designs output by a stereolithography 3D printer. The size is about SA R1 profile.
It's been almost two years since I started making keycaps, but this time I came up with a completely new keycap - Tane.
There are four models available currently: #VRNI is a keycap hollowed out in a Voronoi pattern, #CHES is a keycap with a hole pattern of cheese :), #MESH with a mesh-like surface, finally, #TMESH – a keycap with a triangular hole in the mesh.
The stacking is about 0.0125 mm. These caps are considerably more delicate than a normal ones. When removing from the key switch, be sure to use the key puller and pull it straight out.