There are currently two tests used throughout the corrugated industry
to determine strength. Historically the industry standard has been the Bursting (Mullen) Test, measuring the force required to rupture or puncture the face of corrugated board. This force is indirectly related to a carton's ability to withstand forces to make it suitable to contain and protect a product during shipment. Bursting strength is reported in pounds (for example, 200# test).
A new standard that has achieved acceptance is the Edge Crush Test (ECT). This is a performance test related to the stacking strength of a case. It is measured by compressing a small segment of board on edge between two rigid plates perpendicular to the direction of the
flutes until a peak load is established. This is measured in pounds
per inch of load bearing edge (lb/in), and reported as an ECT value.
(for example, 32 ECT).