Hi,
I have tried to unwrap a surface and with the following material, however, I have been unable to create a seamless wrap. I tried a couple of different experiments, with placement of the seams at different places on the column, but in all cases, the seam was visible in the final render.
Here are a couple of tries, and the latest one in .blend.
credit for the material - blendswap cf material
cf material.blend (642 KB)
Whoa. Accidentally surreal.
Yes, very nice shape…
I was about to suggest box mapping but, before to serve it to you, I decided to taste my own dog food…
(I added some colors to see a little better.)
It seems that box mapping doesn’t work the way I thought. There are some weird fuggly glitches where horizontal planes met vertical planes.
I really can’t think of a way to unwrap such a shape and box mapping doesn’t work… Errr… Good luck for the future. 
