Traditionally, art like this (which includes commission pieces, con sketches, etc) is done under a kind of "gentlemen's agreement". We, the artists, agree that the work is not done for publication, and the copyright owners agree not to pursue any compensation for the use of their property.

That's worked for half a century or so, tho unfortunately, in recent years, some people have been pushing the point by putting out "portfolios" and the like, containing reproductions of con sketches and commissions.

And, of course, we are all waiting to see how Disney deals with this. They have been most zealous in protecting their copyrights, from the very beginning. Now that they own all the Marvel characters, will this alter the equation, or, as some think, is the precedent already set?

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Thanks for the answer JB. Here's hoping Disney doesn't change anything.