Beginner UV help needed

Hey guys,

I’m a complete beginner and have a UV mapping related question.
I created a simple shape, marked a couple of seams, unwrapped it, added the texture I wanted, set up the nodes, but the texture renders different from what I expected. According to what I see on the UV map and the way I marked the seams, shouldn’t the gray area on the bottom be thinner? What am I doing wrong/

Thanks for any tips!

http://imageshack.com/a/img633/5444/15UPfS.png (wireframe and uv / texture)
http://imageshack.com/a/img537/9941/XoN9vq.png (render and node setup)

Seems like you have a subsurf modifier… try switching it off or add a couple of edge loops (ctrl+r) where you want the material “separation”.