A method for electroless coating of a substrate by applying an activating coat of polyelectrolyte or salt with a first aqueous composition, rinsing of the activating coat such that the activating coat is not entirely removed The activated surface that has remained after rinsing is then contacted with an aqueous composition in the form of a solution, emulsion or suspension to form an organic secondary coat (precipitation coat), and drying. The activating coat contains at least one cationic polyelectrolyte or at least one cationic salt in solution in water. The aqueous composition which forms the secondary coat contains constituents which can be precipitated, deposited and/or salted out and which are anionically, zwitterionically, sterically or cationically stabilized. The dry film formed in the process, which is made of the activating coat and the secondary coat, has a thickness of at least 1 μm.