Well, I've seen special effects in the form of
airbrushing (rain, glows etc), but aren't the
really bright glows an effect you can't put on a
cel?  I always assumed they were done using the
same technique used for backlighting.  Does anyone
know differently?  So, though I often love scenes
where there's a glow, I can't always have them...
there are a few I wouldn't mind just have the
black area ^_^

Keys