Abstract: The invention relates to a method for coating a substrate by means of a paint system, said system comprising at least two paint layers, which are applied in succession to the substrate. After said application, a paint enhancer or strengthener is applied to the surface of at least one of the two applied paint layers. The method permits a substrate to be coated in such a way that at least some sections of the paint system (where the paint intensifier has been applied) have an improved mechanical load-bearing capacity, in order to produce e.g. an adhesion point with an improved mechanical stability. The invention also relates to a substrate that is coated with the paint system, to joining methods for a paint system of this type, to joined connections, to the use of bonding mixtures and to multi-ply paint layers comprising areas that have been subsequently cured.