Molecular orientation and mass distribution have been measured in various synthetic polymers using a characterization technique developed by the authors. This method is based on the transmission of polarized far-infrared radiation. Fairly thick samples (polyethylene up to one centimeter thick) can be tested easily with this nondestructive approach. Spatial resolution in the millimeter range is possible. This allows the characterization of various industrial products made of nylon, polyethylene, polypropylene or polyesters, such as liquid containers, injection-molded parts, thick extruded or drawn sheets and rods, etc. Potential scientific and industrial applications are discussed.