I've used those warhammer (citadel?) paints. They are water based and just easy to use on these. They soak the paint up but if you get a good brush it isnt too hard to get nice detail on them. I have had mixed results with shapeways but it may have been because I used the material "white strong and flexible" when I should have used "white detail" or atleast the polished white strong and flexible. Most turned out okay but the Arcee pistols turned out very poorly. I'm going to use them to experiment with paints and see if I can get a smoother finish. I also have a cliffjumpers guns in the same material to paint and a heap more in ultra detail and detail. Just need more time to paint.