Now that I have such a beautiful stencil, the rest should be easy, just spray paint through it. I remember from some previous experiences that spray particles would try to reach behind the stencil and that would make the edges fuzzy. 

For the first test, I used a couple of drops of silicone glue to hold the stencil as close to the key as possible. The result looked promising:

However I didn't like using the glue. I decided to stretch the foil across the keys using two test prints as supports. Here's just a nice picture of sun projecting through the stencil:

(We have sun)

I used some tape, perhaps some other things, but the foil would never stay put. In the end I decided to just use some weights (don't put too much weight on it).

I tried to make the coats as thin as possible using a spray can. After 5 or 6 coats with some 5-7 minutes between I decided that enough is enough and it's time for the grand reveal.

The stencil prints always have these annoying connecting bits which I also had to add, or the stencil would not hold itself together. I touched them up using acrylic white paint on a tip of a smallest brush that I could find. 

I'm going to seal it with transparent lacquer when it's fully set. If I were to try it again, I'd account for the fuzziness and use a thinner font.

Yay.