@ar@is-a.cat
In preparations for #why2025 i made a @hswaw@social.hackerspace.pl logo in the form of pseudo-neon made out of acrylic/PMMA, HDF, and an addressable RGBW led strip. 
like an onion, it has many layers, all 3mm thick
full transparent acrylic on the front
mostly full HDF, with frosted acrylic inserts for diffusing the led strip into the shape of the logo
four structural HDF layers with a single continuous path for the led strip, which is slightly different (somewhat simplified) from the "front" shape
backing PMMA layer, to somewhat protect the led strip, and prevent it from falling out if it unglues itself.
The general shape is based off of a version of the logo @q3k@social.hackerspace.pl designed for the Warsaw Hackerspace website, aptly named "neon-syrenka.svg" ("neon-mermaid.svg"), but it took a few years before a physical representation in a (pseudo-)neon form was created 
most of the "artistic" design i did, including the simplified ledstrip path, was done in Inkscape, with the electronics box designed using FreeCAD