Pre-multiplying eh? Good to know Maybe it happens because you rendered as png? I'm curious about this. I use PNGs cause they're small and high quality, but I know that some people swear by targa, but couldn't find a real reason why, a lot of people say that they use targa at studios, but that's as far as they go.. so it sounds more like a habit than anything else. What the best image file format in your opinion and why?