Say I have a face and I draw some 2D shapes on it in sketchup. Then I want to save this as a texture to apply to the face so I can have a lot of detail on a model with the same amount of polygons.

Here's an example. I have a ramp and I made lines on it to look like non-slip ridges and I want to convert those lines into a texture i can apply to the face of the ramp.