The present invention relates to a method and a system for predicting and/or measuring and correcting geometrical errors in lithography using masks, such as large-area photomasks or reticles, and exposure stations, such as wafer steppers or projection aligners, printing the pattern of said masks on a workpiece, such as a display panel or a semiconductor wafer. A method to compensate for process variations when printing a pattern on a workpiece, including determining a two-dimensional CD profile in said pattern printed on said workpiece, generating a two-dimensional compensation file to equalize fluctuations in said two-dimensional CD-profile, and patterning a workpiece with said two-dimensional compensation file.