This is a hand painted column based on the tutorial https://www.youtube.com/watch?v=L7ALfRw6I5I. Did 90% of the painting in Blender. For roughness map, I painted a specular map, inverted it and used some CgCookie's brushes to paint additional reflective surfaces. Kent Trammel's CgCookie courses on texturing (specifically Portalethium and rock asset) helped a lot.
kkcent Thanks kcent
Very nice! I too watched that video and it really helped me get an idea what you can accomplish with texture paint and simple brushes. I love what you've done here. :)