To export a geometry or a group of geometry to a RIB archive, select the objects, go to the object properties , and under the RenderMan Geometry panel, select Export and then Export Object as Archive
You can also select whether or not you want the materials that are assigned to the geometry to be exported and whether or not you want to archive all of the frames.
If you anticipate needing to override the material that's on the objects in the archive, uncheck Export Material
You can import a RIB archive from the Add menu.
If you want to attach a material to the RIB archive, you can do that using the Material Override panel in the object properties . NOTE: if there is already a material attached on the object in the archive itself, then that will take precedence.