sig
  type metals =
      T_Brass_1A
    | T_Brass_1B
    | T_Brass_1C
    | T_Brass_1D
    | T_Brass_1E
    | T_Brass_2A
    | T_Brass_2B
    | T_Brass_2C
    | T_Brass_2D
    | T_Brass_2E
    | T_Brass_3A
    | T_Brass_3B
    | T_Brass_3C
    | T_Brass_3D
    | T_Brass_3E
    | T_Brass_4A
    | T_Brass_4B
    | T_Brass_4C
    | T_Brass_4D
    | T_Brass_4E
    | T_Brass_5A
    | T_Brass_5B
    | T_Brass_5C
    | T_Brass_5D
    | T_Brass_5E
    | T_Copper_1A
    | T_Copper_1B
    | T_Copper_1C
    | T_Copper_1D
    | T_Copper_1E
    | T_Copper_2A
    | T_Copper_2B
    | T_Copper_2C
    | T_Copper_2D
    | T_Copper_2E
    | T_Copper_3A
    | T_Copper_3B
    | T_Copper_3C
    | T_Copper_3D
    | T_Copper_3E
    | T_Copper_4A
  val to_string : Povray.Textures.Metal.metals -> string
end