The invention relates to a cutter (10) for cutting printed substrates, said cutter (10) comprising a supporting plane(20) adapted to receive a printed substrate (30) comprising a plurality of images (31) separated by a plurality of edges (32, 33) perpendicular to each other in a feeding direction (F), and a plurality of cutting units (50) suitable for cutting said printed substrate (30) along said edges (32, 33) in a longitudinal direction (L), parallel to said feed direction (F), and in a transverse (T), perpendicular to said feeding direction (F). Each cutting unit (50) comprises a pair of parallel blades (51), spaced apart at a distance corresponding to the width of the edges (32, 33), a backing plane (53) arranged underneath the supporting plane (20) of the cutter (10) and suitable to provide a backing surface to said blades (51) during cutting, and a connecting arm (54) which extends from a frame (55) of the cutting unit (50) on which the blades (51) are mounted to said backing plane (53) in a direction opposite to the cutting direction. The connecting arm (54) is parallel to the blades (51) and is arranged between the blades (51) on a plane (P) parallel to the planes (A, B) on which the blades (51) lie, and the portion of the backing plane (53) comprised between the area arranged underneath the blades (51) and the area wherein the connecting arm (54) is fixed comprises a through opening (56). Thanks to this configuration, the edges (32, 33) between the images printed on the substrate (30) may be cut in a single step by the cutting units and substrate scraps may be separated directly during cutting operations without the need for manual intervention of an operator.