Abstract: A method and system for gauging deviations of a surface of a test part from a preselected nominal surface profile is disclosed. The system includes a support having a master surface that is substantially a matched or mating surface of the nominal surface profile of the test part and a thin layer of an attenuating medium such as a dye liquid between the master and test surfaces. Electromagnetic radiation is directed through the support and master surface and through the attenuating layer onto the reflective surface of the test part. An image sensor such as a camera is positioned to receive an image of the radiation reflected by the test part surface back through the attenuating layer and support, with the intensity of such radiation across the image varying as a function of the deviation of the test part surface from the nominal surface profile.