I 've been using TVPaint for everything for our animation studio
from storyboards/animatics/ frame by frame manipulation/correction/editing
and tons of illustrations/character design/comics .
I will start a daily comic /sketch/ series called Tautologies
here is a little preview
http://www.facebook.com/tautologos
http://tautologos.tumblr.com/
http://www.socomic.gr/2012/08/tautologos/
and of course the little intro vide was tvp as well
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hope u like them
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and hope u enjoy them
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J.