The invention relates to a method for producing a microbial substance-releasing layer on a technical surface. The inventive method comprises three steps: a) producing a solution from polyvinylacetate, a preservative agent and a solvent, b) applying the solution to the technical surface, and c) drying the solution applied to the technical surface while forming the layer. The inventive method is characterized by using benzoic acid, sorbic acid, natamycin, bacteriocines, plant extracts or mixtures thereof as the preservative agent and an ethanol/water mixture, ethyl acetate or acetone as the solvent.