A size composition for the surface sizing of paper, board or other suchlike. The size composition comprises a size fraction which comprises a water-soluble, principal component made up of, for example, starch, polyvinyl alcohol, carboxymethyl cellulose, glucomannan, protein, or mixtures thereof, and a pigment fraction formed by mixing together a mineral material, which in the main comprises talc particles and/or other phyllosilicate particles, and a binder such as a synthetic polymer, latex and/or other corresponding binder. The size composition is prepared by mixing together the said size fraction and pigment fraction.