If I were looking to hire someone to create a book cover for me, I probably wouldn’t hire a pure artist to design it.

I might commission an artist to create art for my cover, but I would hire a designer—one experienced in publishing—to design my cover with that artwork.

Someone might make beautiful paintings, but they might also have an affinity for Papyrus, not know the difference between straight and curly quotes, or not know how to fix those rivers of type on your back cover (let alone know what rivers of type are)!