UV Mapping - How to use multiples materials and images for one object

[micheus]

Lets say you have a model with 2 materials, metal and wood. You go through the AutoUV tool and it creates a new material that everything gets assigned to, you no longer have metal and wood.

If I understood right, start with two different materials and then create an uvmapped material that include the entire area used by both was not the scope of this thread. I'm going to update the first post to mention this. Thanks to explain and let me know if that post is still not clear enough.

But, in this case, what I use to do is make the selection area, paint each area (using the palette) and creating a selection group (as you do) - just this. If everything will be put in the trash after apply the UVmap, there is no reason to create materials and the selection groups is enough.
Also, you still have the possibility to used the vertex colours to tint each face when creating the texture.