You can also put the DS materials in the poser library if you give them a dummy Poser file - DSmaterials.duf and DSmaterials.png need DSmaterials.pz2 (or any other Poser file extension) and when you look in the Poser library folder you will see the thumbnail with a scroll icon at top-left, indicating that there is a native DS companion files that DS will load instead of the Poser file when you double-click.