Hi, I decided to make it CC-0 for the time being.
"for the time being" Be careful, once its CC0 you are allowed to change the licence any time, but everyone who already got it may upload it under a different license. You are no longer copyright owner.
If you want you can add that an attribution is welcome, but not required. I usually attribute, even if not required.
Thanks for sharing this art with us, its beautiful!
once its CC0 you are allowed to change the licence any time, but everyone who already got it may upload it under a different license.
That’s not that different from how other general public licenses (eg. CC-BY, CC-BY-SA, MIT, GPL, etc.) work.
Not being able to revoke permission from someone who’s following the rules and them being able to share what they received on the same terms even after you stopped offering those terms is par for the course. Likewise, you can modify something under the CC-BY or MIT licenses to create a new work and license that work under the CC-BY-SA or GPL, because nothing in the CC-BY-SA or GPL contradicts what you’re already bound to comply with by the CC-BY or MIT licenses. That’s what “GPL-compatible” means in software licensing.
Heck, the Debian Free Software Guidelines tests irrevocability as part of what they call the “tentacles of evil test”. (Basically, if a company like Oracle buys the rights to it, can they make life miserable for previous recipients of a license.)
The big difference with a public domain dedication is that, with a general public license, you can change your mind and people will be bound by the terms they received it under while, if you put something into the public domain, and then change your mind, and then sell someone a license, they’re essentially only paying you to actually get access to the files and they’re still in the public domain. (Unless you add new stuff that wasn’t released into the public domain, in which case those new/modified files aren’t in the public domain as long as copyright law considers the additions to be big enough and transformative enough to qualify for copyright protection.)
With a license, if you change the license before anyone downloads it, that’s it. With a public domain dedication, if someone saves proof that it was ever CC0’d, it’s still CC0’d. That’s what it means to waive your rights.
A general public license cares about having a valid chain of “I received the rights and then gave them to…” while a public domain dedication is only concerned with proof that the rightsholder gave up their right to impose restrictions. That’s why the Creative Commons website has warnings when you choose the CC0 form.
If you can demonstrate that what you have is what was put into the public domain, it doesn’t matter how you got it beyond the usual laws about computer hacking and burglary and so on.