Is it legal for me to do this? And is this commonly done? Does this look bad on me as an artist? I haven't ever sold prints before, so I really have no idea. I haven't sold the customer the copyright to the image, just charged them for rendering the image like is typically done. Some of my commission pieces I would like to sell as prints at a future con because they turned out really well.
(I would obviously ask the commissioner if it's okay with them, since it's their fursona in the picture.)