What brush do people use to make popouts, they always have like a decaying grungy look at the borders then it goes a little black, when i make them the border is always like solid and gross, i can never find a brush that makes it look good

I believe you got your answer here
http://forums.d2jsp.org/topic.php?t=68073605&f=105

Just use C4Ds to make the shape. Turn the lightness all the way down so they're solid black and then add the rest of the layers on clip masking. It looks better and cleaner than just using brushes.