At the hardware store I stumbled upon decorative perforated aluminum sheet, and gave it a try on a sample MDF piece:
It was also the opportunity to cut my very first aluminum parts with the Shapeoko, which went smoothly.
I think I’ll do a full MDF prototype version of the lamp this way, see how it looks, and go from there. I already spotted much nicer perforated sheets with interesting patterns.
Thanks again for the idea and the file!