Organic electroluminescent devices (OLEDs) comprise very thin layers of organic substances on top of a glass substrate covered with an electrically conducting but optically transparent oxide, usually Indium-Tin oxide (ITO). ITO forms the substrate electrode, usually the anode and a layer of Aluminum (100 nm) evaporated on top of the organic layer stack forms the counter electrode, usually the cathode. When a voltage between 2 and typically 5 V is applied between the electrodes, current is injected into the organic layers and light is generated. The preparation of OLEDs requires structuring of all individual layers to provide a reliable operation over time, in particular to operate the OLEDs, both electrodes have to be electrically isolated from each other. Therefore at least three masks processes are commonly required: structuring of the substrate electrode deposited on top of the substrate (first mask process), depositing the organic layer stack on top of the pre-structured substrate electrode (second mask process different to the first mask process) and depositing the counter electrode on top of the organic layer stack without providing an electrical contact to the substrate electrode (third mask process different to first and second mask process). The mask processes apply so-called shadow masks having different geometries in order to cover the desired areas with the layer to be deposited and simultaneously shielding the other areas in order to avoid material deposition there. The application of shadow masks for deposition (coating) processes is expensive, because the masks have to be manufactured with high geometric accuracy. Furthermore masks will be coated with the deposited material and have to be cleaned periodically. Misalignments of masks may lead to deposition failures making the operation of OLEDs impossible, e.g. by electrically shortened electrodes due to a misalignment of the counter electrode mask. A lot of additional measures have to be applied in order to achieve a reliable coating process making this process very expensive, see for example EP 1202329 A2. All these measures result in a manufacturing process requiring an enormous effort to achieve a good production yield (low failure ratio).