Abstract: A mounting device of a lithoplate, having a head clamp and a tail clamp of a lithoplate provided at a cutout portion of a plate cylinder, includes a register pin fixed to a lower blade of the head such that it penetrates through and projects from an upper blade of the head clamp. A clamp provided to the mounting device of a lithoplate includes a clamp having a register pin at an upper surface of an upper blade of the clamp and a roller which can freely rotate is provided at the position of a plate cylinder side opposed to the register pin. The mounting device of a lithoplate also includes a device for covering at least a part of a lithoplate holding tail edge at a region between a tip of a vise at a tail side and a plate cylinder to which no pressure is applied.

Abstract: Disclosed is a light-sensitive element for lithographic printing plates excellent in stain resistance and water-carrying capacity which comprises a support and, coated thereon in succession, at least one undercoat layer, a silver halide emulsion layer and a physical development nuclei layer wherein at least one of the layers on the silver halide emulsion layer-provided side of the support contains 0.1-2.0 g/m.sup.2 of a matting agent of 5.mu. in average particle size and the light-sensitive element has an arithmetical mean deviation of profile Ra of 1.2 or less.