Patent ID: 8398802

Claim:
A method comprising the steps of: adjusting moisture content in a traveling web of medium material by applying a substantially continuous first thin film comprising water and adhesive to an exposed surface thereof so that said web of medium material comprises 6-9 wt. % moisture following the adjustment; thereafter heating said web of medium material to a temperature less than or equal to about 100° C., such that said medium material retains 6-9 wt. % liquid moisture therein after said heating as a result of said adjusting step; and thereafter corrugating said web of medium material, wherein said surface remains exposed during said corrugating, to produce a corrugated web, wherein said web of medium material retains 6-9 wt. % moisture, and is at temperature less than or equal to about 100° C., immediately prior to said corrugating step as a result of said adjusting step.