For forming plastics, radiant heat with an IRt/c is an excellent combination of heating method and control. They work extraordinarily well together since both the heating and measuring occur right at the surface, where the plastic is located. The IRt/c reading is unaffected by reflections from the heater since the spectral response of the 6 to 14-micron IRt/c lens filters out the shorter wavelengths of the radiant heater energy.