Natural Kraft Linerboard

Natural (Brown) Kraft Linerboard

Natural cardboard offers the perfect surface for an organic look. Made from 80% virgin wood fiber, it is 100% recyclable and biodegradable.

Recyclable and biodegradable
Available in different flutes
Organic texture

Best Used With

Folding Carton Boxes Corrugated Boxes Rigid Boxes Rigid Tube Floor Displays Wine Bags Food Packaging

Overview

Natural kraft board, made from 80% virgin pulp fiber, is up to 100% recyclable and biodegradable. Brown in color, it offers optimal durability, tear resistance, and dust resistance, making it ideal for shipping product packaging. As the industry standard for corrugated packaging, natural kraft board is readily available and cost-effective to produce. However, its brown color may cause printed designs to appear more muted or faded. For brands requiring vibrant designs, investing in bleached white or Kemi white liner boards, despite the higher cost, might be worthwhile.

Corrugated Board Process

Flute Types & Formation

Corrugated Formation

Flute Types

Corrugated Board Performance

Single Wall

Min. Burst Strength (lbs/sq in)	Min. Edge Crush Test (lbs/in)	Min. Combined Weight of Facings (lbs/m sq ft)	Max Weight of Box and Contents (lbs)	Max Outside Dimensions (L + W + D in)
125 lbs/sq in	23 lbs/in	52 lbs/m sq ft	20 lbs	40 in
150 lbs/sq in	26 lbs/in	66 lbs/m sq ft	35 lbs	50 in
175 lbs/sq in	29 lbs/in	75 lbs/m sq ft	50 lbs	60 in
200 lbs/sq in	32 lbs/in	84 lbs/m sq ft	65 lbs	75 in
250 lbs/sq in	40 lbs/in	111 lbs/m sq ft	80 lbs	85 in
275 lbs/sq in	44 lbs/in	138 lbs/m sq ft	95 lbs	95 in
350 lbs/sq in	55 lbs/in	180 lbs/m sq ft	120 lbs	105 in

Double Wall

Min. Burst Strength (lbs/sq in)	Min. Edge Crush Test (lbs/in)	Min. Combined Weight of Facings (lbs/m sq ft)	Max Weight of Box and Contents (lbs)	Max Outside Dimensions (L + W + D in)
200 lbs/sq in	42 lbs/in	92 lbs/m sq ft	80 lbs	85 in
275 lbs/sq in	48 lbs/in	110 lbs/m sq ft	100 lbs	95 in
350 lbs/sq in	51 lbs/in	126 lbs/m sq ft	120 lbs	105 in
400 lbs/sq in	61 lbs/in	180 lbs/m sq ft	140 lbs	110 in
500 lbs/sq in	71 lbs/in	222 lbs/m sq ft	160 lbs	115 in
600 lbs/sq in	82 lbs/in	270 lbs/m sq ft	180 lbs	120 in

Triple Wall

Min. Burst Strength (lbs/sq in)	Min. Edge Crust Test (lbs/in)	Min. Combined Weight of Facings (lbs/m sq ft)	Max Weight of Box and Contents (lbs)	Max Outside Dimensions (L + W + D in)
700 lbs/sq in	67 lbs/in	168 lbs/m sq ft	240 lbs	111 in
900 lbs/sq in	80 lbs/in	222 lbs/m sq ft	260 lbs	115 in
1100 lbs/sq in	90 lbs/in	264 lbs/m sq ft	280 lbs	120 in
1300 lbs/sq in	112 lbs/in	360 lbs/m sq ft	300 lbs	125 in

E-Flute

Min. Burst Strength (lbs/sq in)	Min. Edge Crust Test (lbs/in)	Min. Combined Weight of Facings (lbs/m sq ft)	Max Weight of Box and Contents (lbs)	Max Outside Dimensions (L + W + D in)
150 lbs/sq in	26 lbs/in	66 lbs/m sq ft	35 lbs	50 in
200 lbs/sq in	32 lbs/in	84 lbs/m sq ft	65 lbs	75 in

Corrugated Strength Tests

Edge Crush Test (ECT)

Force is applied perpendicular to the edge of the corrugated board until it buckles. This test provides an accurate measure of the material's strength, durability, and stack resistance for heavier loads. The resulting value, shown in pounds per linear inch of load-bearing edge, is reported as ECT (Edge Crush Test) ratings.
Note: 32 ECT is the most commonly used for corrugated material.

Bursting Test

The burst test, also known as the Mullen Test, evaluates the durability of the corrugated fiberboard’s surface. It measures the amount of force required to puncture the liner board, with the resulting value given in pounds per square inch.
Note: 200# means 200 pounds per square inch of force applied to the face of the liner board.

Corrugated Strength Tests