Coatings are applied in various industries and to various materials, e.g. plastic, metal or glass. Manufacturers and users encounter various challenges here, for example adhesion strength. The necessary adhesion strength for paint application is a question of surface energy and surface polarity. This surface energy can be significantly increased by plasma treatment. Surface pretreatment with Openair-Plasma achieves clean and highly active surfaces, on which even water wets well. The use of solvents to "swell" the surface is therefore no longer necessary. The entire plasma process is dry and wastewater-free, so it is also a more environmentally friendly process than the previous use of solvents and similar products.