Waviness is a shape deviation of technical surfaces. Waviness is therefore a parameter that provides information about the shape of objects. Alongside roughness, it is one of the most important elements of surface quality of molds. Waviness is divided into shape deviation classes of a total of six orders. If the required surface finishes specified in the technical drawing and the real surface finish differ, a defect exists. These shape deviations can usually be detected on the surface, provided they are in the first, second, third or fourth order. However, even in the case of these recognizable shape deviations, more detailed statements can usually be made about their characteristics if they are examined and tested for their surface quality using suitable measurement techniques of surface measurement. Defects of the fifth and sixth order can only be detected by specialized microscopy equipment and methods. Electron microscopes, for example, are suitable for this purpose.