Especially at high circuit boards there is the risk of the paint to be very thin at their edges. More precisely, the coating thickness at the edge radius is very low especially at reduced viscosity. At fine-line structures the lacquer may pass over the path. This can be prevented by a plasma treatment with Openair® plasma in the following way: Since plasma can increase the surface tension above 72 mN/m the wettability of lacquers is even more homogenous. This leads to an optimal distribution of the lacquer so that even edges get covered very well.