Key out background and keep "halo" around foreground Noob here! I captured video of myself writing on my ipad- pure white background with pure black text. I want to import this into Blender 2.8 and overlay it on top of another video, obviously removing the white background. BUT I would like to keep a few pixels of the white so that the text will remain legible even if the new video background becomes dark in places. What is the best way to do that?
I followed a YouTube video about chromakey and used the Keying Node, tweaked the feathering settings, but the best I can get is something like this:

The feathering seems to &quot;miss&quot; bits of my text, and the fluffy cloud look isn't really what I want anyway. Really I would like to just keep a few pixels of white running around the edges of all the black. Am I on the wrong track entirely? Thanks!
You don't need to key the text. Just multiply it over the background image.

For legibility you can add a fake drop shadow, by multiplying a version of the same text displaced and blured:

Or if you need white, then use the dilate/erode node in feather mode, invert the result,  and use color dodge to add a soft white border around the letters.

Or use the black writing as a mask to have color text.