Adding borders to overlay clips
You can add a border to an overlay clip. For example, you add a white border around an image to make it look more like a photo.
To add a border to an Overlay clip
1	In the Attribute tab, click Mask & Chroma Key. 
2	Click the Border arrow keys to set the thickness of the border for the Overlay clip. 
3	Click the Border color box located beside the arrow keys to set the color of the border.