Thanks Neil. That’s actually what I’m currently doing. To give you a little more context. I’m creating box effects to showcase several clips in the frame at once. Using PIP with a border (promoted 3D) is clunky because you have to crop each image as it flies on and if you only want a white border on say one side of a clip, you have to zoom into the clip to obscure the other sides (because the border will always show up all around). Also, it makes shot replacement hell because you basically have to redo all the animation because the crop and position keyframes won’t be the same on two different clips and with more than 2 clips, it becomes unwieldy.
My solution was to create black and white mattes using the paint tool for the boxes, and then on top of everything, use the paint tool to make little white bars to create the “borders”. They can be animated once, and then applied to multiple sections of the edit and all I have to do is step in and replace the shots. It kinda looks like this (using simulated footage):

The problem with building and animating anything with the paint effect is that there doesn’t seem to be a way to stop the keyframes from being “elastic”. That is, when I subclip the effect to my bin and apply it elsewhere to other footage that is longer than the original effect, the keyframes are stretched out and the animation is slower. I’m trying to see if there’s a way to default all animations to fixed keyframes like you can in the advanced keyframe area of the effect editor. Does that make sense?
Andy
https://plus.google.com/u/0/107277729326633563425/videos