Corrugated cardboard in carton box design

Corrugated fiberboard is a paper-based material regularly madeof a fluted corrugated sheet along with one or two flat linerboards. It is extensively used in the manufacture of corrugated boxes and shipping containers.

The corrugated medium and linerboard are designed of containerboard, a paper-like material usually over 0.01 inches (0.25 mm) thick. Paperboard and corrugated fiberboard are usually called cardboard, although cardboard might be any heavy paper-pulp based board.

Corrugated flute sizes are "A", "B", "C", "E" and "F" or microflute. The letter designation relates to the order that the flutes were invented, not the relative sizes. Flute size refers to the number of flutes per lineal foot, although the actual flute dimensions for different corrugator manufacuturers may vary slightly. Measuring the number of flutes per lineal foot is a more reliable method of identifying flute size than measuring board thickness, which can vary due to manufacturing conditions. The most common flute size in corrugated boxes is "C" flute.

Standard US Corrugated flute

Flute Designation Flutes per linear foot Flute thickness (in) Flutes per linear meter Flute thickness (mm) A flute 33 +/− 3 3/16 108 +/− 10 4.8 B flute 47 +/− 3 1/8 154 +/− 10 3.2 C flute 39 +/− 3 5/32 128 +/− 10 4.0 E flute 90 +/− 4 1/16 295 +/− 13 1.6 F flute 128 +/− 4 1/32 420 +/− 13 0.8
Corrugated cardboard was invented in the mid-19th century and has been used widely in nowadays.