made using a conventional electrical coil heater. The pigment dispersion was slowly added with stirring and converted to a thick paste. The paste after 2 h curing was compressed uniaxially into a form of cylindrical discs using a hydraulic press (Lawrence & Maya, India) at a pressure of 25 MPa. Both sides of the pigmented polymer were lapped using a fine grade emery sheet for obtaining a polished surface. The intensity of the color of plastics will depend on the concentration of the pigment.