Hey Dave,
I tried doing what was written in the link you provided but when I opened the upper layer Track Matte mode it only gave me options to select a different clip that was above the upper layer, not the layer below that it was duplicated from.
Am I missing something here?
Here’s what the link says:
҉ۢ Duplicate the keyed footage, and turn off the upper layer.
• Fool with the lower layer’s Keylight settings until it looks like the subject looks fine, but is over a grayish, washed-out chroma key background. It’ll take some doing, but you will have gotten it to the point where Keylight’s spill suppressor is working. That’s good, because the Keylight spill suppressor works darned well.
• Open the Modes panel, and use the upper layer as an Alpha Matte for the lower layer. For more info, look up Track Mattes in AE Help.
Poof! You’re done! You have a clean key, AND you have spill suppression.”