a method for structuring a surface includes , by an assigned modification device , creating a latent structure of at least a first layer of the surface , which has a polymer therein , so as to form hydrophilic and hydrophobic regions for producing a printing form for offset printing , by selectively applying a gaseous , readily volatile solvent as a modifying agent to at least one locally limited region of the surface over at least one exposure time interval . a device for performing the method , a printing form exposer , a printing unit and a printing machine including the surface - structuring device according to the invention , are also provided .