Thanks, that did it.
As for why I want to do this...
I am making a map where players have the option of moving through tubes (cylinder textured on both sides).
Had this not worked for some obscure reason... I would have created a cylinder textured on the outside, duplicated it, scale down it's diameter by 1-2 units, reversed the side it was textured on, and finally placed it in the cylinder textured on the ouside.
It was a long inefficient method, that's why I asked here.