Patent ID: 8382946

Claim:
A method for coating a paper web with a paper surface sizing composition, comprising the following steps: (a) providing an uncoated or a single-side coated paper web having first and second surfaces; and (b) providing a liquid paper surface sizing composition comprising: an acicular calcium carbonate paper pigment having an aspect ratio in the range of from about 4 to about 10 and a low particulate surface area, in terms of a BET specific surface area, f about 30 msg or less; a paper starch binder; and a paper co-binder; wherein the starch binder comprises from about 50 to about 95% by weight of the total combined weight of starch and co-binder; wherein the co-binder comprises from about 5 to about 50% by weight of the total combined weight of the starch binder and the co-binder; wherein the pigment to the combined starch binder/co-binder weight ratio is in the range of from about 0.5 to about 4; wherein the composition has a Brookfield viscosity in the range of from about 20 to about 500 centipoise; wherein the composition has a solids content of at least about 12% by weight; and (c) treating at least one of the first and second surfaces of the paper web of step (a) with the paper surface size composition of step (b), to apply a paper surface size coating thereon, wherein the paper surface size loading on each surface on which the paper surface size coating is present is in an amount from about 0.5 to about 4 gsm, to thereby impart to the treated surfaces an opacity value of at least about 85 and a print show-through value of about 0.02 or less.