Question related to the Syrae thread.

[torinir2.livejournal.com]

With the Syrae thread devolving into a copyright war of words, I figured it was time ask this question. I separated it from the Syrae thread since it might be useful for both artists and commissioners to take note of this discussion.

What are the rules of the land as far as commissioned artwork involving the commissioner's character(s)? I would assume that the commissioner has some recourse when dealing with works involving his/her characters, and the artist has some recourse available by default, but who has the final say as to who can do what with the finished product, in terms of alterations, etc? What kind of timeframe should a commissioner hold for approaching the artist for changes, and when would it be a DIY case?

I'm not talking about generic artwork commissions, I'm speaking of commissions involving characters whose "existence" predates the artwork being commissioned.