Corrugated sheets have developed with a basic concept in mind. The fluted medium is affixed to the liners with a starch adhesive. Once affixed the integrated board resists bending. The flutes provide cushioning when pressure is applied from the sides and when placed on end, they form stiff columns capable of supporting a great deal of weight. The commonly used flutes are C and B flute and others include A, E, and F flute. Generally, larger flutes offer greater vertical compression strength and cushioning. Smaller flutes offer printability advantages as well as structural advantages for retail packaging.

Flute Designation Flutes per Linear Metre Flute Thickness (mm) Flute Cross Section
A Flute 108±10 4.76
B Flute(Auto) 154±10 3.18
C Flute(Auto) 128±10 3.97
E Flute 295±13 1.59