I've got a knight mini I've already painted up and he looks pretty sweet. However, I've decided I want him like a 'green knight', but don't want to strip and repaint. Assuming I can paint over sealed paint, what would be a better way to go to get the desired green tint effect as used below....layers of green glaze or green wash?
Wash will only end up in the deeper spots, so that won't work like you want, probably. You can paint right over a sealed miniature, no problem, though. When I get a base coat and some detail and I'm happy with it, I seal it before moving on so if I screw up in the future I can just wipe/rinse it back to that last "save point", so to speak.
I'm not sure what you're looking to do, though. If that mini above is yours, and you're looking to make his armor green or something, or give it a green tint, you can just use a thinned normal paint (not a wash, but thinner) and use a sponge or brush, or if you have an airbrush, I'd airbrush it so you have some control over the tint.
Yeah, just paint over the original silver. Maybe mix some silver armor paint (Chainmail/Mithril) with a touch of dark green so it still shines but is green. That's probably the simplest. The layers will probably also give a cool effect.
Surprisingly, I've never messed with glazes, so I can't comment on how they work. If it's like ceramic glazes (which I have used on ceramic) where its more of a thick, sem-transparent color) then you can probably try that first.
Personally I'd use a green wash to get the effect in the picture (at least for the armour and the horse's barding). I think you might be better off using a base cost of some sort of off-white colour rather than silver. Something bone-coloured maybe? Once the wash has dried perhaps use a little silver to highlight here and there, to give the impression that it's metal. The 'plumage' (for want of a better word) would be a more traditional paint job.
Have you checked GW's new gem technicals? But that's very glossy. Depending on the effect I want, I'd use green wash over white or silver. Don't worry about washes only going to the cracks. The faint tint and the greenish shade will make it looks green. If you want the "safe route", I'd just paint silver with green edge highlighting.
If you're willing to do some experiment, then use shade. They take some more work to ensure definition, and I'm usually less sure on how a certain shade would look over a color. EDIT: I was meaning *glaze* in this paragraph...
Agree with most others - silver base (maybe mixed with a touch of green), followed by a green wash. Edge highlight with silver if you're feeling adventurous. Job done!