I just discovered the work of Mexican artist Rafael Gallur on DeviantArt.com recently. I can't tell you much about him, except that his work is all traditional materials (i'm thinking gouache and acrylic for these painted joints) and he has done lots of work for Western and Luchador comics (like this comic page he did for Arena Magazine ). His painted covers are bonkers! here's some favorites below...
In addition to Arena, I liked the western stuff in his DeviantArt gallery, like the covers he did for LA LEY DEL REVOLVER.
dude is nuts, right? you can peep more of his stuff here.