
Originally Posted by
Sigma-Astra
As an actual professional artist, let me just weigh my experience and thoughts on this.
Selling fan art that has been made solely by yourself isn't considered RMT, however, there are many grey areas and lines that you can cross and ones where you shouldn't touch them with a ten foot pole. I would be careful about advertising such things on the official forums themselves through a new topic/thread simply because it is a reportable thing and could be considered advertising or spam if someone was really petty enough. However, that being said, there's nothing against the rules as far as I am aware of that you can't advertise your tumblr or DeviantART page through your own signature. So, that is probably going to be the best way you could advertise your freelancing without someone's jimmies getting rustled over it (so long as your link doesn't contain a virus or unsavory images like pornography).
Now, usually creating fan art grants you the Creative Commons License in which you have sole ownership and trademark over what you yourself has created. Still, license or not, that won't stop art thieves or copycats from stealing your hard work. Depending on what country the thief originated from and depending on their....personality....usually once something is stolen there's very little you can do about it besides asking them politely to NOT do it. I mean, you could try to sue them, but the costs of legal action is probably not worth it. That's one of the sadder parts of freelancing your art and posting it on the internet since a lot of people think anything on Google is fair game to copy and steal as their own (it's not, don't do it).
Regarding the trademark and infringement topics, in order for someone to claim that what they make is truly fan art and no where near the capacity of the original, it has to CLEARLY look like your own self-made style with various tweaks, etc. Tracing original art is NOT fan art, it's stealing. I don't care how much time and effort it took you to trace over that trademarked and already existing character, it's not your own art. If it looks anywhere exact or close enough towards the original. You stole it, plain and simple. I don't care if you changed the hair color or eye color, or whatever, it's still stolen work and it's rude.
Companies that I have learned over the years to stay away from because they do not take kindly towards anything and will jump at you the first chance they get are Marvel and Disney. Other companies like Nike, Apple, etc don't really take kindly towards you using their logos without permission either, but that's an entirely different part of the field and subject matter away from fanart.
The bottom line is to just be smart about it. You know when you've done something wrong or stole something. You know when you've made something too close towards someone else's work. It's fine to use other artists as inspiration and role models, but those artists don't want you to copy their styles exactly either. And it's good to know that not everything you find on tumblr, Google, Instagram, pinterest, and other social media are fair game to use without someone's permission. References are okay, but that's all they should stay as, as references...and your final product should not look perfectly too close towards the reference pieces.