subject to some limitations, a posersurface with a texmap or simple colour in alt_diff channel is not affected by the poser directional lites.  e.g. said surface will not receive shadows cast from objects between it and a directional lite, nor will it be illuminated by said lite (subject to some limitations).  place a request in the poser 9 thread for an additional lite property called "restrict lighting to these objects", with all selected by default.