Thanks for your input, stv and Cole.  I think I 
will just leave the tape alone for now.  If it 
is like regular ol' scotch tape, it will 
eventually get so yellow and brittle that it 
will just fall off on its own.  (Hopefully it 
won't destroy the cel with some horrible "sticky 
tape gas emissions" in the meantime! :)  And 
it's nice to know that having cut-outs isn't 
completely unheard of.  (It really does give a 
nice effect to the cel when viewed in person -- 
3D)  And thanks for the heads-up on the 
conservation glass.  That was the first thing I 
bought when I decided to frame them myself.  I'm 
also building a wooden folding screen/room 
divider kind of thing to hang my framed cels on, 
so I can move the wall they're hanging on -- so 
as the seasons change and the sun comes in at 
different angles, I can move the whole wall out 
of the direct light.  (Maybe I'm getting 
obsessive here! Naaaaaah.  ^__^ )
shellie