This book was written for the practitioner with the aim of presenting characteristics and methods of roughness measurement in an easily understandable form. Definitions of the surface parameters can be found in the relevant standards. Older parameters are also explained, to the extent that they still have a worthwhile meaning today. In practice, it is quite common to leave the entries in the drawings unchanged over the entire life cycle of a product. This is based on the valid ISO standards. This guide "Surface texture - Theory and practical use" is intended to explain the different roughness parameters and make it easier for the designer to specify surface parameters.