Abstract: An extremely thin, high flute density, printable, corrugated paperboard having a combined caliper thickness of about 0.040 inches or less includes a first flat paper liner about 0.0085 to 0.010 inches thick, a corrugated medium having a paper thickness of about 0.005 to 0.008 inches, with the flute dimensions including a cordal flute height of about 0.021 inches and a distance between flute crests of about 0.070 inches, and a second flat paper liner about 0.0065 to 0.01 inches thick, the composite paperboard product having about 181 flutes per linear foot. The process for manufacturing the corrugated paperboard includes novel steps for forming the flutes in a manner which will not cause wrinkling or tearing of the paper stock, and the application of a novel adhesive formulation having solid content of about 28.8 percent and a Steinhall viscosity of about 23 seconds.