Rotative printing machine with auto-tensionable ruler, it deals with an auto-tensionable ruler (1) by spring (2) contiguous to the movable bushing (3), both annexed to the main axle (4) that receives by extreme connection (5) the printing paste spilled by holes (6), in order to make possible the scattering of said paste in the interior of the cylinder (7), in this manner making possible the preparation and/or assembly of surplus sets of stamping (CE) outside the machine (M), being the relative position of the said sets demarcated in points of reference (15) in the bushing (8) and in the flange (16) receiver of the cylinder (7).