A surface-treatment agent containing at least one type of processed starch selected from a) to c) as listed below is applied to a base paper of a newspaper so that a product of a B-type viscosity of the surface-treatment agent, measured under conditions of 10% concentration at 50 C. (rotor No. 1 at 60 rpm), and an application amount of the surface-treatment agent (both sides) is within a range of 2 to 15 cpsg/m²;

• a) Etherified starch, which is etherified by the compound defined in the general formula (1) given below:

• wherein A represents an ethylene group or propylene group, while n represents an integer of 1 to 15,
• b) Carboxylic acid esterified starch, which is esterified by monocarboxylic acid or dicarboxylic acid containing a linear, branched or cyclic alkyl group or alkenyl group having carbon atoms of 4 to 18, and
• c) Aldehyde starch.