#Zero Black
You don't have to set it to 0,0,0… no background is the same thing.
DonL's points are excellent…. PLUS, the CORRECT way to do this is with an
alpha matte in an ABC-roll environment by shoving the matte into the switchers
key channel. 3D Studio produces a perfect matte by rendering in 32-bit mode
and turning Alpha-Split ON.
– G