File used by Indigo Renderer, a program used for generating photorealistic 3D images; contains a material, which stores graphical properties that give the surface of a 3D object a realistic appearance, such as that of metal, wood, plastic, brick, or another material; can be included as part of an Indigo Renderer scene (.IGS file).

Many IGM files can be downloaded from Indigo Renderer's website for free. NOTE: IGM files are saved in an XML format, but may be compressed in the .PIGM format, which is more suitable for sharing due to the reduced file size.