Has anyone tried something like this for numbers and such?...like liquitex paint markers,I wonder if they would work over black? http://www.liquitex.com/paintmarkers/
I have not had much luck using paint markers for numbers and such. I have some Pilot markers that I use for detailing drivers, other markers that I tried that had felt or nylon tips were useless. You might be able to find these markers at Hobby Lobby or Michaels, you could buy a couple and give them a try.
I use Krylon paint markers for lots of things, and they are tough. My mailbox is decorated with them. That's some tough paint- county road, 100's in the summer, -15 in the winter, rain, snow, etc. Lasted 5 years so far.