A library file will open with comments // or * inside the { } Poser will not keep them for me on resave. However This - added into the Materials section - will stay until manually deleted - i.e. Poser will keep it in on resave. (You cannot put comments as a texture call, it will look for a texture by that name. So, the length of the comment is determined by low long a material name can be. The neat thing is - this shows up in the materials menu in Poser. material Copyright-2002-by-Jaager { KdColor 1 1 1 1 KaColor 0 0 0 1 KsColor 0 0 0 1 TextureColor 0.8 0.8 0.8 1 NsExponent 100 tMin 0 tMax 0 tExpo 0 bumpStrength 1 ksIgnoreTexture 0 reflectThruLights 0 reflectThruKd 0 textureMap NO_MAP bumpMap NO_MAP reflectionMap NO_MAP transparencyMap NO_MAP ReflectionColor 0 0 0 1 reflectionStrength 0 } This should keep the data in more or less forever for 99% of Poser users, what with the phobia against text editing a poser file. I just checked - UVMapper strips old comments and will remove a usemtl line that has no associated facets. So this is not a way to keep comments in an OBJ file.