I'm wondering by which method this sort of aircraft panel that enabling backlighting are made? What is the process? I've gathered they are acrylic but how is the gray paint selectively removed?
This video says the following:
Here's my Tonson TS-3040C CNC making an EFIS panel for my flight simulator. For the lettering I am using a 0.4mm End Mill and for cutting out I'm using a 1mm End Mill. RPM is 10000 and movement is 300mm / Min. The material is Cast Acrylic which I have given one coat of black paint and two coats of grey paint.
So that's at least one method, but there are probably more...
It's a 3 layer color system with white opaque special laser colour, a black light block layer, and the final colour. For military it stays black without the 3rd one. After spray painting the special laser color is removed with a laser system. You can see it here.
This page has some good information and a graphic, looks like the same as shown in the video Manfred posted. Clear plastic with an opaque layer that is engraved off, and lighted from beneath.