So I do a lot of layering work on my renders - generally to add backgrounds without adding massive render times - and, thanks to the alpha channels Studio automatically creates with .png files, this is pretty easy. But I do have one reoccurring problem that frustrates me. Inevitably the top layer has a thin line of white around the added content. Usually it's not enough to bother me much, but when rendering hair the problem becomes extremely visible -- a large white halo around the character's head that I have to go in and fix by hand.

Has anyone found any tricks for getting around this issue?