Thank you for all your answers!
I have a Cricut vinyl cutter at home so printing stickers isn't a problem. But from my experience it is really hard to get the letters cut out exactly right so it only fills in the deep part of the lettering. That's why I want to paint it so I can get it more precise. I'm going to try Phak1's idea.
Again thank you for your ideas and answers!
Thijs