Cels Forum

The seal of the Studio Pierrot thing doesn't decrease the 
value.  Basically it's a little sticker on the cel, it's 
not an impression that is crushed into the cel.  I know 
cause I have a few ^_^. And I think they do put it on all 
the cels they release since the show is licensed by them.  
But if you're planning on buying the cel from the Studio
Pierrot website in Japan, they don't ship out of the country.
IE Their cels only stay in Japan, unless you have a friend
in Japan help you forward it to the US or wherever.

Satoshi