Bump Texture Painting isn't working on seashell

Ignore this post. I figured out what I did wrong.

I am attempting to follow a tutorial here: http://www.youtube.com/watch?v=K45RINbtQYc I can not paint the bump texture in gray. Then when I render it, I don’t see any bumps. I was able to get the bumps on my first shell (although I still wasn’t able to paint in gray) but now I can not get the bumps to show up when I render. Can someone look at my blend file and tell me what I am doing wrong?

Screenshot of my seashell

Link to my blend file: