It should be against the rules to have a signature over a certain size..

Come to think of it, do we even have a forum rules page? Should make one, since I only yesterday found the thread with those rules and whatnot.

Hmm. Rule page says signatures are bound by the rules above it. Which includes no "messy posts". Which could probably be stretched to cover obnoxious signatures.

There is a text limit but there is no image limit that I know of.