When polylactic acid (PLA) is annealed under properly controlled conditions, it provides a significantly stiffer and stronger part with increased heat deflection temperatures. Strength is found to increase by up to 40% and stiffness can be shown to increase up to 25%. Parts made from annealed PLA outperform polycarbonate (PC) and SLS nylon PA2200 in XY axis strength. Furthermore, annealed PLA parts have demonstrated heat deflection temperatures of up to 180°C, equal to that of Ultem. This enhanced strength along with a higher glass transition temperature, allows for a much broader set of practical applications.