> same deal. Those black lines aren't hand inked
> in this scene. They're pure copy-toner.

How do you know ? There isn't any specific rules.
Sometime, they hand-ink over the the flashed
line because they weren't good enough. Sometime
they do it just for one cel of the sequence
for whatever reason...

Try it : just put some alcohol over it : I am
ready to bet it will erase your lines. (but
don't complain after... :)

Cheers,
Yann Stettler