Fair use, in the US anyway, is based on four factors (source):
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
Not selling fan art helps to bolster factor #1, though that alone isn’t enough. Fair use itself would need to be determined by a judge, but ensuring the work is transformative enough and doesn’t disincentivize someone from purchasing the original work is probably enough commercial or not, but noncommercial theoretically should help.
(Not a lawyer, but I’ve followed this a bit)
Edit: note that fan art could be fair use but violate a trademark or other similar protected mark.
So, no commissions or patreon support if you are drawing fan art, got it.
Fair use, in the US anyway, is based on four factors (source):
Not selling fan art helps to bolster factor #1, though that alone isn’t enough. Fair use itself would need to be determined by a judge, but ensuring the work is transformative enough and doesn’t disincentivize someone from purchasing the original work is probably enough commercial or not, but noncommercial theoretically should help.
(Not a lawyer, but I’ve followed this a bit)
Edit: note that fan art could be fair use but violate a trademark or other similar protected mark.