A method for producing a pattern of hydrophilic (34) and hydrophobic (32)
regions on a printing form (30) is presented which, in a first, essentially
unpatterned state, features a polymer material containing imide groups, for example,
polybenzene diimide or polyamide imide. The method includes a chemical treatment
of the surface with an oxidizing agent subsequent in time to a locally selective
exposure with UV light. Optionally, the locally selective exposure can be preceded
by a large-area chemical treatment of the surface with a strong base. The printing
form (30) can be restored to the first state by a large-area chemical treatment
of the surface with a strong acid. The patterned printing form (30) is suitable
for use in offset printing.
