Pie, your talking about the one outlines like on 21rc1ogt's flames right? Alot of them are done and the outline is done with the mask. Its a whole seperate mask within a mask (Kinda hard to explain). Id imagine itd be pretty tough to get it to line up as straight as a mask when doing it freehand, but I suppose its possible. I was wondering that also. Looks really nice and clean.