I have this little logo animation that needs to be sent to editors for overlaying with video footage, they need a transparent background version... It's a simple logo animation on a white background. However, there are masks in the animation, so when I export with alpha, some parts are transparent but the parts where the masks are stay white, which creates weird transparency aeras when overlaying.
How do get rid of this, or make the export alpha the masks as well...
What kind of layer are these masks on?
You might consider dropping your whole composition into another composition and rendering that one out. Also turn the transparency grid on and off; see if it shows transparency in those areas.