A low thermal inertia mold (LTIM) is evaluated based on its ability to reduce residual stress and molecular orientation in thin polycarbonate parts. The mold employs a special cavity design which incorporates the use of high-temperature (above 350 °C) thermoelectric devices. Residual stresses are compared in LTIM and conventionally molded parts via an estimation of critical J-integral values (Jc)-the essential energy needed for crack initiation per unit area. The estimated values ofJcfor LTIM and conventional parts are 6.3 and 7.3 kJ/m2, respectively. This difference may be due to the elevated LTIM cavity temperature which alleviates residual stresses and in turn reduces the estimated value ofJc.Observations of birefringence distributions were used to compare molecular orientation. The amount of birefringence is greatly reduced in a large central region of the LTIM parts, indicating low levels of orientation. Conventional parts show distinct color fringes along the melt flow path, indicative of flow-induced orientation.