.mtl file references the "usemtl" statements in the .obj file to texture map and materials values. The .obj file usually contains nothing but vertices, faces, etc., in group seperated by tiny statements like: g hip or usemtl redwood A .mtl file is much like the materials section in a Poser cr2; # Created By Carrara 1.0 newmtl Hilt Ns 163 d 1 Ni 0.001 illum 2 Ka 0.2 0.2 0.2 Kd 0.5 0.5 0.5 Ks 0.25 0.25 0.25 Make sense?