To set material type, use the pull down menu located below the Material Name field. Currently only plastic and metal may be created. Plastic includes all opaque materials which have colored diffuse reflections but uncolored specular (shiny) components. Plastic materials include formica, tile, glossy paint, and any similar surfaces. Materials that have colored specular highlights are appropriately modeled as "metal". Metal materials include bronze, gold, copper, aluminum, and similar surfaces. (More on this in Physical Properties)
