make custom (illuminated?) pushbutton caps

Hi!

every now and then I want to make custom pushbuttons. A special shape, size, color, text, whatever. I did not find a good solution until today. E.g. think about an aircraft cockpit, there are different knobs and buttons.

I think the most obvious possibility would be to print them with a 3D printer, make a cast out of it and then cast it with resin. But this only gives me the shape. I also want to have writing on it, and maybe finally, illuminate the text. (example: http://www.gadgetnutz.com/wp-content/uploads/2013/04/LogitechK810-review-32.jpg)

Do you have any idea how I could realise something like this?

Thanks for any hints :)

My 3D printer (A TAZ 4) can print in 2 colours. However the precision is not sufficient to print letters any smaller than about 1cm tall and those look pretty splodgy as the material oozes during printing. A finer nozzle may improve the result but I don't expect it to ever print keyboard keys.

I would guess that the online services with the expensive printers might be able to do a better job.