PURPOSE: To enhance dryability of an oil base ink, by using an aqueous resin dispersion by emulsion polymerization of a polymerizable monomeric mixture comprising a specified polymerizable monomer, as an aqueous overcoating composition for a surface printed in an oil base ink.

CONSTITUTION: A polymerizable monomeric mixture comprising an ester of acrylic acid and/or methacrylic acid of the general formula, wherein R1 is a hydrogen atom or a methyl group, and R2 is a 6W18C aliphatic or alicyclic hydrocarbon group, in an amount of not less than 15wt%, preferably, 20W50wt%, is subjected to emulsion polymerization by using a hydrophilic catalyst such as ammonium persulfate or a redox catalyst, and an emulsifier such as an anionic surfactant is added thereto as required to obtain a composition comprising a water-dispersed resin as a main constituent. The composition is applied to an oil base ink in the wet state immediately after printing, by a coating means provided in a printing process.