Thanks!
Actually, I'm very mixed about what to do with battle backgrounds. There is a bit of history. The main problem is the game is set in a lot of different places, and I can't find a decent source of homogeneous looking 2d background for each one, or backgrounds that looks like "how I want it to look".
Since I used to play Ragnarok Online, I know the game pretty well, and have a good idea of what ingame location would be good to use as a background. Fact is that I just wander around in the mmorpg until I find a perfect spot and use it as a battlebackground.
But using screenshots of a old 3d game with low res texture, in contrast with detailed sprite and in a completely 2d game, made it look a bit weird. Hence the choice of making them look like paint.
Indeed, it would be awesome to find a source of decent and 2d looking background, if you have any recommendations perhaps.