Abstract: A printability improving agent for use in a neutral newsprint base paper which is printed with ecological inks, containing (I) a cationic copolymer obtained by polymerizing one or more hydrophobic monomer unit(s) selected from styrenes and alkyl acrylates and/or alkyl methacrylates with a quaternary ammonium salt-containing monomer unit, and (II) a copolymer obtained by polymerizing 100 parts by weight of one or more hydrophobic monomer(s) selected from the group above in the presence of 1-10 parts by weight of a surfactant.

Abstract: Provide a paper offering good paper strength properties in terms of strength and stiffness, high smoothness and excellent printing quality by adjusting the ash content in paper to a range of 3 to 40 percent by solid weight and allowing the paper to contain a pre-coagulated filler having an average particle size of 10 to 80 ?m as measured by the laser diffraction method, wherein such filler is obtained by processing a filler using a composite acrylamide copolymer comprising (A) an anionic polysaccharide and (B) a cationic and/or amphoteric acrylamide copolymer.

Abstract: The present invention aims to provide printability improving agents and surface-treating agents capable of improving offset printability of papers, especially newsprint papers to be printed with offset inks as well as papers, especially newsprint papers that can be successfully printed with offset inks. According to a first aspect of the present invention, a printability improving agent comprising a cationic copolymer consisting of one or more hydrophobic monomer unit(s) selected from a specific group and a quaternary ammonium salt-containing monomer unit or a surface-treating agent comprising the printability improving agent and a water-soluble polymer material selected from a specific group is applied on the surface of a base paper, especially a newsprint base paper.