Corrugated cardboard is easy to recognize. It is made of paper and has an arched layer, called "fluting," between smooth sheets, called "liner." The corrugated cardboard most commonly used to make boxes has one layer of fluting between two smooth sheets. But there are many types of corrugated available, each with different flute sizes and thicknesses.

Corrugated is an extremely durable, versatile, innovative and lightweight material used for custom-manufactured shipping containers, packaging and point-of-purchase displays, in addition to numerous non-traditional applications ranging from pallets to children's toys to furniture.

Corrugated fiberboard, or combined board, has two main components: the linerboard and the medium. Both are made of a special kind of heavy paper called containerboard. Linerboard is the flat facing that adheres to the medium. The medium is the wavy, fluted paper in between the liners.