A wire printing head (10) for a high resolution printing machine is provided together with a method for its manufacture. The printer is of the type comprising a printing platen (12) for a recording medium (17) and a carriage (11) transversely movable with respect to the printing platen and mounting the printing head. The head comprises a guide matrix (29) adjacent the platen and a plurality of wires or needles (28) guided by the matrix. The wires are capable of longitudinal movement and define on the recording medium printing dots having an area less than the nominal section Sn of the wires. Each wire comprises a front portion (72) of constant section (Sr) which is reduced with respect to the nominal section (Sn) and extends for a minimised length of between 0.5 and 4 times inclusive the diameter (Dr) of the reduced section. The guide matrix supports slidably a terminal portion of the wires comprising the nominal section and lodges with play the frontal portion having the reduced section.