The invention relates to a method for improving the wettability and/or adhesivity of plastic surfaces, in particular, to facilitate printing, painting or adhesion. A lubricant is added to the plastic, particularly to improve the processability thereof. According to the invention, a metal soap-free lubricant is used as a lubricant for the plastic. Alternatively, the wettability and/or the adhesivity of the polyamide surfaces can be improved, especially in order to facilitate printing, painting or adhesion, by increasing the number of end groups of polyamides, optionally maintaining metal soaps as lubricants.