Natural Kraft Board
Natural Kraft paper is a strong, eco-friendly material made from unbleached pulp, giving it its signature brown color and organic appearance. It offers excellent tear resistance, sustainability, and versatility across multiple packaging applications.
Benefits
• High durability
• 100% recyclable and biodegradable
• Natural, earthy look
• Cost-effective
Best Used With
Corrugated Paper & Board
Corrugated paper and board are strong, lightweight, and eco-friendly packaging materials used for shipping, storage, and protection. Made with linerboards and a fluted inner layer, they offer excellent durability, cushioning, and cost efficiency.
Natural kraft corrugated board is recyclable and biodegradable, providing a sustainable, natural look. For brighter and more vibrant printing, white or coated liners are recommended.
Key Features
- Strong and durable for shipping and stacking
- Eco-friendly and recyclable material
- Cost-effective for bulk production
- Excellent cushioning and protection
- Suitable for e-commerce, retail, and industrial use
Printing Notes
- Best for minimal or natural branding
- Colors appear softer on kraft surfaces
- White or coated liners improve print vibrancy
| Feature | Natural Kraft | White Kraft | Coated Paper |
|---|---|---|---|
| Appearance | Brown, organic | Clean white | Glossy or matte |
| Sustainability | Excellent | Good | Moderate |
| Strength | Very strong | Strong | Medium |
| Print Quality | Moderate | Good | Excellent |
| Ideal For | Eco-packaging, wraps | Premium bags, boxes | High-end printing |
Types of Kraft Paper
Natural Brown Kraft
Unbleached, durable, and eco-friendly. Great for wrapping, retail bags, and shipping protection.
White Kraft
Bleached for a clean, premium look while maintaining strength. Ideal for printed retail packaging and food wraps.
Black Kraft
Bold and modern, used in luxury packaging and high-contrast branding.
Colored Kraft
Available in various colors for decorative packaging, gift wraps, and custom branding.
Coated Kraft
Glossy or matte coating for enhanced print quality. Suitable for folding cartons and premium boxes.
Recycled Kraft
Made from recycled fibers. Eco-friendly choice for sustainable packaging and fillers.
CORRUGATED BOARD PROCESS
Corrugated Board Lamination Process
The image illustrates how a coated surface and an offset printed liner are laminated onto a single-face corrugated sheet to create a strong, durable, and visually appealing packaging material. This process is widely used for premium corrugated boxes, retail packaging, and e-commerce shipping cartons.
Coated Surface (Top Layer)
The top layer adds a smooth, protective finish that enhances print quality and improves resistance to moisture, scratches, and handling. It gives the box a premium, branded appearance
Offset Printed Liner (Middle Layer)
This sheet carries high-quality printed graphics, logos, and designs. Offset printing ensures sharp details, consistent colors, and a professional finish—ideal for custom packaging.
Single-Face Corrugated Layer (Bottom Structure)
Made of a fluted medium and inner liner, this layer provides strength and cushioning. It helps the box withstand pressure, stacking, and shipping impacts.
Why It Matters
This process combines structural durability with high-quality print presentation, creating packaging that is strong, protective, and visually impressive. It is essential for brands that require both performance and premium aesthetics in their corrugated packaging.
Flute Types & Formation
Corrugated Formation
Flute Types
Corrugated Board Performance
| 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 | 23 | 52 | 20 | 40 |
| 150 | 26 | 66 | 35 | 50 |
| 175 | 29 | 75 | 50 | 60 |
| 200 | 32 | 84 | 65 | 75 |
| 250 | 40 | 111 | 80 | 85 |
| 275 | 44 | 138 | 95 | 95 |
| 350 | 55 | 180 | 120 | 105 |
| 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 | 42 | 92 | 80 | 85 |
| 275 | 48 | 110 | 100 | 95 |
| 350 | 51 | 126 | 120 | 105 |
| 400 | 61 | 180 | 140 | 110 |
| 500 | 71 | 222 | 160 | 115 |
| 600 | 82 | 270 | 180 | 120 |
| 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) |
|---|---|---|---|---|
| 700 | 67 | 168 | 240 | 111 |
| 900 | 80 | 222 | 260 | 115 |
| 1100 | 90 | 264 | 280 | 120 |
| 1300 | 112 | 360 | 300 | 125 |
| 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) |
|---|---|---|---|---|
| 150 | 26 | 66 | 35 | 50 |
| 200 | 32 | 84 | 65 | 75 |
Corrugated Strength Tests
Understanding Corrugated Strength Tests
Corrugated packaging strength is measured using two key tests: Edge Crush Test (ECT) and Mullen Burst Test. Each evaluates a different performance aspect of corrugated board.
Edge Crush Test – Measuring Stacking & Compression Strength
Measures stacking and compression strength by applying force to the board’s edge.
Higher ECT means better load-bearing and stacking durability.
Common rating: 32 ECT
Mullen Burst Test – Measuring Resistance to Puncture
Measures resistance to puncture by applying pressure to the board’s surface until it bursts.
Indicates linerboard durability and impact resistance.
Example: 200# burst = 200 psi before failure
Why It Matters
ECT is best for stacking strength; Mullen is best for impact resistance—ensuring the right board is chosen for safe shipping.
Color Appearance On Kraft Board
Colors Printing on Natural Kraft Board
When inks are applied directly onto unbleached kraft paper, the natural brown surface absorbs some of the pigment. This can make colors look softer, deeper, and slightly subdued compared to printing on white paper. The result is a warm, organic look that complements eco-friendly or rustic packaging styles.
Color Printing with a White Base Layer
Applying a layer of white ink beneath the printed colors helps them appear brighter and more saturated on kraft material. This method keeps the natural kraft texture visible while dramatically improving color accuracy, offering the best combination of vibrant design and authentic kraft appeal.
White Ink Printing on Kraft Paper
Printing with white ink on kraft paper produces bold, high-contrast graphics that highlight the natural texture of the material. This technique is often used for minimalistic or premium designs, creating a striking visual effect without the need for full-color printing.