A guiding element for a printing unit is provided to facilitate use of the printing unit in an imprinter function. In one operating situation, a strip is printed as it passes through a printing gap of the printing unit. In another operating situation, the strip is guided through the printing gap by the guiding element in a non-contact manner. The guiding element includes, on the outer surface, a plurality of openings adapted for the discharge of a pressurized fluid. These openings are micro-openings of a diameter less than 500 .mu.m.