A method for aligning the leading edge of printing plate (110) to an axially disposed slot (70) in a cylindrical surface (30) of an imaging drum (20) comprising at least one printing plate clamp (90) having a clamp surface (100) disposed parallel to the slot, the method comprising straightening (210) the leading edge against the clamp surface and positioning (220) the leading edge to protrude over the slot by rotating the imaging drum under the plate. The straightening comprises resting (200) the leading edge of the plate on the cylindrical surface of the imaging drum and rotating the imaging drum about its cylindrical axis (60) to contact with the clamp surface a point along the leading edge of the plate and to rotate the plate until its leading edge is in alignment with the clamp surface.