Hi. I am decorating a dining room and have removed a piece of hardboard that was blocking the fire place. Behind the wood the tiles have been removed leaving what I assume is concrete. The surface is raised where the tiles have been removed. I am deciding what to do to improve the appearance as the texture pattern left behind is ok but needs painting. How do I prepare a surface like this? What paint should I use? I do not want to cover the whole thing up again.