Abstract: The invention relates to a method for manufacturing a coating composition for a printing substrate. Method comprises mixing together colloidal silica particles, and an aqueous dispersion of a synthetic polymer and/or polyaluminium chloride, as well as a binder solution. The obtained mixture is used for forming a coating composition to be applied on the printing substrate comprising lignocellulosic fibres. The invention also relates to a coating composition comprising binder and a dispersed cationic component derived from synthetic polymer and colloidal silica particles.