Checkout this 3D Printed Keyboard. I used PLA for the base tray, and Natural (Transparent) PLA for the lid. Lid is using 20% infill to allow the light to be defused, and it was printed at 220 to get the clearest layers for the top. Also, this was printed on PEI, so the surface is a nice glossy surface.
I designed this to hold the denser 48 LED/m pixel strips. The long keys hold 3 pixels, and the short keys hold 2. This makes for an effective keyboard effect, but can also be used for some neat matrix effects.
STL files available here:
