The present invention pertains to an aqueous surface-coating agent for paper and paperboard, the aqueous surface-coating agent comprising 1-55 wt.% of solid content and containing (A) 0-20 parts by weight of starch (solid), (B) 0.01-20 parts by weight of a zirconium carbonate composition, and (C) 0.01-40 parts by weight of a synthetic water soluble polymer (solid) comprising one or more monomers with monoethylenic double bonds in the polymerized form. The present invention further pertains to a paper and paperboard manufacturing method using the aqueous surface-coating agent, and corrugated board made from said paper.
