Engineered molded fiberboard panels and methods of making and using the same

A panel, comprising:

• an elongated sheet of molded fiberboard material of corrugated shape having opposite first and second faces and opposite side edges, each face having a plurality of alternating, longitudinally extending ribs and grooves extending along the length of the sheet, the ribs on the first face each having a first peak and the ribs on the second face each having a second peak facing in the opposite direction to the first peaks;
• the sheet having at least one slotted portion which has a plurality of spaced slits, each slit extending lengthwise across at least a plurality of the first peaks and being cut through part of the ribs of the first face including the first peaks to a depth less than the depth of the grooves in the first face and terminating short of the second peaks of the second face;
• the panel being formed into at least one curve extending along at least part of the length of the sheet at said one, slotted portion with the slotted first face of the sheet facing inward;
• and
• the slits are closed with adhesive at least at the first peaks of the ribs on the inwardly curved first face of the sheet.