Patent ID: 7892613

Claim:
A paper or paperboard substrate having substantially parallel top and bottom surfaces consisting of: a base ply having top and bottom surfaces, the base ply comprising ligno cellulosic fibers having a first brightness x; a top ply having a substantially white color top and bottom surfaces, the top ply comprising ligno cellulosic fibers having a second brightness y which is greater than the first brightness x and wherein the top surface of the top ply forms the top surface of the paperboard substrate; and an intermediate layer having top and bottom surfaces, the intermediate layer positioned between the top and base plies to reduce a basis weight of the top ply, the intermediate layer comprising from about 50% to about 70% by weight of organic and from about 30% to about 50% by weight of inorganic material, wherein the intermediate layer is configured such that the paper or paperboard substrate has a top surface third brightness z and wherein the third brightness z is greater than the first brightness x and is equal to or less than the second brightness y.