DDS files (used in MAT files) look the same in game as in for example milkshape
also, using UTF editor you can open existing MAT files, and export textures in DDS format to be used while texturing (or you can use already exported ones - download link is somewhere in this part of forums). But when you export the model material names must be named exactly the same as their counter part inside the vanilla MAT. So using UTF you can check the names, later you simply point the game in shiparch what mat to load with your model. And you can use multiple mat files and only some textures from within.....
