Anything that appears on the overlapping areas of a single material zone will appear on both front and back, making it hard to place symbols or to have things join up between front and back. If the areas did not overlap, or if they are separate materials and so able to take separate textures (which is Randy’s work-around) then that problem goes away.
So, I guess you are talking about creating textures for clothing in a program like Photoshop. Once you follow Randall’s video tip to fix the UV map, how do you get that fixed UV map into Photoshop to use it as a guide to making the textures? (As you can guess, I’ve never done this!)