In this photo, you can observe the now completed battery of artillery -- 1/72 plastic crew manning two 25mm MiniFigs cannon -- belonging to the Grand Duchy of Stollen. Painting the black metal work on the red gun carriages was time consuming but worth it. The gloss finish seems to make all of the colors richer.
Except for some flesh tone by Windsor Alkyd Artists' Colors (an oil-based paint that dries in 24 hours), all other colors are acrylics produced by Games Workshop. Most of these have terrific coverage properties -- even over a black base coat.