[Boatanchors] Panel painting question-engraved lettering

[WW6N]

I am painting a TV-7 tube tester panel. I sprayed aluminium primer and then navy gray paint.
Then engraved letterings need be filled with white color. I wonder what to use to fill in the letterings. 
I tried white correction fluid and water based white paint but both turned out difficult to remove excess paint.
Could someone suggest what to use?
Thank you in advance.