Box Strength

Box Strength is measured in two different ways:

Mullen Test

Measures resistance to rupture in pounds per square inch (psi).

Single Wall: 150, 175, 200, 250, 275, 350
Double Wall: 200, 275, 350, 400, 500, 600

Edge Crush Test (ECT)

Measures ability of combined board to sustain a top-to-bottom load. The strength is directly related to the compression strength of both the liners and medium.

Single Wall: 26, 29, 32, 44
Double Wall: 48, 51, 61, 71