For all my artistic pursuits outside and on canvas, I use the gold Krylon 18K leafing pen. It is the juiciest paint marker I have ever dealt with and the only one I ever use.
Many people ask me if I use real gold on my canvases because I always have 18K gold listed as one of my mediums. But no, that leafing pen in the middle is it. Best part is, I can cover two huge wall canvases with just ONE pen. I don't know where the paint keeps coming from, but these have never failed me when covering huge surfaces. It's even what I used to fill-in all my Tuts!
If you want to jazz up anything, even your kicks, then I highly recommend leafing pens. They create a super fine metallic gloss that is great to add to any robotic design or to fill-in logos and stripes. Plus, they work on all surfaces and never seem to quit.
Rack a few up at your local Michaels or art supplies store.
