Is there any other reason, other than the fact 
that the sequence is back lit, for a cel to be 
painted all black on the back? I know the 
sequence the cel is from, and it's not one. It's 
a B cel from a sequence where the A cels are used 
over and over again. 
(Does this help, or is it useless information?) 
(Argh -- I don't want to think about the 
possibility that the paints there to cover up the 
words, "This is just a copy.")