So one day my friend show'd me some paper-craft masks she made from wintercroft templates. I immediately thought I had to make one covered in LEDs.
After downloading their design for the Fox Half Mask I opened it in Fusion360 so I could copy the outline for each polygon in to a DXF before transferring that to Altium. I thought for a while if there was a more efficient way to layout approximately 300 LED's, but since each polygon was different I ended up just doing it by hand while watching the entire second season of Succession. Each edge is flanked 3 holes on each side for power, signal and ground (plus some extras for strength). The idea is to place a loop of wire across each pair, transferring current while also making a hinge. Once everything is hooked together I can fold the mask in to its final shape and solder everything down.
In order to make things slightly simpler, I sourced the 5th version (with integrated bypass caps) of the WS2812B directly from World Semi.
Many hours later I fired off an order to JLC. A few days after that I got these guys:
I didn't take many progress pics, but I laser cut a kapton stencil, did the whole reflow thing and then singulated each polygon with a bandsaw. In the future I'd pull the ground and power pours further back from the edge so they don't get exposed when cut.