Sizing method and sizing composition for use therein

In the method of producing sized paper wherein there is employed in the internal or external sizing thereof an aqueous emulsion of a hydrophobic cellulose reactive sizing agent selected from the group consisting of ketene dimers, acid anhydrides, and organic isocyanates, the improvement wherein there is employed in combination with the sizing agent a sizing accelerator, said accelerator being selected from a water-soluble poly(diallylamine)-epihalohydrin resin and a water-soluble poly(N-methyldiallylamine)-epihalohydrin resin in an amount sufficient to increase the off-the-machine sizing effect of the sizing agent, the amount of epihalohydrin used in reaction with the poly(diallylamine) being from about 0.5 mole to about 1.5 moles per mole of secondary amine present in the polymer and the amount used in reaction with the poly(N-methyldiallylamine) being from about 0.5 mole to about 1.5 moles per mole of tertiary amine present in the polymer.