Advice - Selling prints of Commissioned pieces

[quescostumes.livejournal.com]

I've recently heard of an artist who is selling prints that contains other people's characters. The art and style is her own, and the art with characters are either gifts or commissions. The prints for sale include the original piece uploaded to art sites, without any recoloring or hiding others' characters. Should people buy these prints, it's basically making money off of others' designs, right?

It's not okay, right? Is it legal? Rude? Or just frowned upon?

How should someone handle this kind of situation if the artist in question is a friend?

Any advice, A_B?

Edit: Thanks everyone for your very useful replies! :)

Comments

[aerotheacrobat.livejournal.com]

I sell prints of commissions/trades/gifts I've done. I even explain in my TOS I do because it keeps my prices cheap. I've never had anyone have an issue and I give them a free print if I come across them at cons. If you're worried, ask the people it's for before selling a print.

[nambroth.livejournal.com]

I sell prints of commissions/trades/gifts I've done. I even explain in my TOS I do because it keeps my prices cheap.

This is exactly how I work. I've only had a few people* that were not okay with it, and I worked something out with them and I don't sell prints of their commissions.
(*Referring to private, individual commissions. I always negotiate image rights independently on pro freelance via contact)