So is it CC0?
Is it hand work not AI?
Viewing post in Annako's Backgrounds comments
It's not AI generated as far as my knowledge goes. And annoka mentioned that they don't mind the art being used commercially but because they used certain effects/brushes developed by others as apart of the artwork, there is a chance that the work is not 100% originally made (sort of like drawing your own background and then adding stock images for effect). So in a way, it's little bit more of a risk to use it in commercial projects. That's my interpretation at least