Yes, but how do you know the original image is out of copyright? It’s mostly obvious for older pieces, but for newer ones it’s not always obvious when an artist

Yes, but how do you know the original image is out of copyright? It’s mostly obvious for older pieces, but for newer ones it’s not always obvious when an artist painted a work. Even with apparently older images, the worry is that the photo is actually of a reworking of an older piece that isn’t out of copyright. This would be solved by linking each photo back to the originating gallery. (I contribute to Standard Ebooks – https://standardebooks.org/ https://standardebooks.org/ – and would like to use Artvee’s imagery for covers, but without a link back to the originating site to check for a CC0 grant it ends up being a trawl through Hathi looking for photographic proof that the image is out of copyright.)