A printing form (10) having a surface (12) of pure silicon or of a silicon ceramic, which bears a pattern composed of hydrophilic and hydrophobic regions, the hydrophilic regions having a first chemical state and the hydrophobic regions having a second chemical state that differs from the first chemical state, in hydrophobic regions, the surface (12) having silicon atoms, to which at least one organic terminal group is attached in each instance. The organic terminal group may be, in particular, an unsubstituted or halogenated aryl terminal group or alkyl terminal group and be attached via an Si--C, Si--O--C or Si--O--Si--C bond. Also a method for modifying the wetting properties of the printing form, the surface (12) being brought into a first chemical state having a first wetting property, and a portion of all regions of the surface (12) being brought into a second chemical state having a second wetting property by modifying the chemical terminal groups of the surface (12).