Billions of boxes of corrugated material are shipped around the globe each year. They can transport items ranging from food to electronics, clothing, auto parts, furniture, and more, that move from one location to another. But most people just take them for granted, picking any box that happens to be available without considering the type of flute, wall construction or the ratings for the edge crush test.
That is a very expensive error! The right corrugated box can translate into products that do not get damaged, shipments that are not lost, and money that are not spent on an over-designed package.
This information will help you make the correct decision and understand what a corrugated box is, how it is made, the various types and sizes of corrugated, and how to choose the right corrugated box for your product.
What Is a Corrugated Box?
A corrugated box is a packaging box formed from corrugated fiberboard—composed of two flat, adhesive outer and inner boards that are held to form a corrugated box by a wavy, fluted paper core—that's stuck in between with a starch-based adhesive.
It's the shape of the wave that's important. The fluted medium adds strength to the box and is able to absorb pressure and distribute weight much better than a flat sheet of the same paper.
Key components:
- Outer liner — the exterior facing, usually kraft paper, which is printed on
- Inner liner — the interior facing that contacts your product
- Fluted medium — the corrugated wavy layer sandwiched between the liners
- Starch adhesive — water-based glue bonding the layers together
How a corrugated box is different from cardboard
“Corrugated” and “cardboard” are colloquially used interchangeably but they are not synonymous. The corrugated medium is the multi-layered structure which gives corrugated fiberboard its strength. A cardboard (or paperboard) is a single-ply thick sheet, like a cereal box or greeting card. A corrugated carton box can take the same stacking weight as a cardboard carton box and not collapse.
How Corrugated Boxes Are Made
There is more precision involved in the manufacturing process than is apparent.
Raw materials: The materials used in making corrugated boxes are most commonly kraft paper (virgin wood pulp) or recycled paper. Depending on the supplier and grade, the recycled content can be 70-100% post-consumer. The adhesive is, in most cases, corn-starch based, meaning that it's non-toxic and water-soluble (recycling later is important).
Manufacturing steps:
- Corrugation — Paper medium passes through heated fluted rollers to impress the corrugation pattern into the paper
- Bonding — The fluted sheet is bonded on a corrugator machine to the linerboards.
- Printing — Flexographic or Digital printing on outer liner (before or after board conversion)
- Cutting and creasing – Rotary dies or steel-rule dies cut and score the flat sheet to make box blanks.
- Folding and gluing — Blanks are folded into box shape and glued, stapled or taped at the manufacturers seam
Sustainability: Corrugated is one of the most recycled packaging materials in the world and in many markets has a recovery rate greater than 90%. One of the only truly circular packaging formats today is corrugated fiberboard boxes, which are being transformed back into new linerboard and medium with repulping.
Types of Corrugated Board (Wall Constructions)
The number of layers in a corrugated board determines its strength, weight, and appropriate applications.
|
Wall Type |
Layers |
Typical ECT Range |
Best For |
|
Single-face |
1 liner + 1 medium |
N/A (not a standalone box) |
Wrapping, cushioning, void fill |
|
Single-wall (3-ply) |
2 liners + 1 medium |
23–55 ECT |
Standard shipping, e-commerce, retail |
|
Double-wall (5-ply) |
3 liners + 2 mediums |
42–71 ECT |
Heavy products, long transit, industrial |
|
Triple-wall (7-ply) |
4 liners + 3 mediums |
67–112 ECT |
Very heavy parts, bulk industrial, palletized loads |
3 ply corrugated box is the most common box used for ecommerce and retail shipping, being light enough for cost, yet strong enough for most consumers' products.
5 ply corrugated box : When transporting bulk goods, appliances, beverages or anything that has to endure pallet stacking or rough handling, there's no better choice than 5 ply corrugated box.
Also Read:- What Is the Difference Between 3 Ply and 5 Ply Corrugated Boxes
Flute Profiles Explained
The thickness of the corrugated board, the cushioning capability and the ability to print on the board is controlled by flute. As important as selecting wall construction is, it is just as important to choose the right flute.
A-Flute Largest flute - (about 4.7mm thick, 36 flutes per foot). Exceptional cushioning and stacking qualities. For fragile items and outer boxes for shipping. Not suitable for good printing.
B-Flute Smaller flute - approximately 2.4mm, 50 flute per foot. Good puncture properties and better printability than A. Is widely used in canned products, glass containers, and product display containers.
C-Flute Middle ground - (approx. 3.6mm, 41 flutes per foot). Strikes a balance between reasonable cushioning and good printing. The flute most commonly used in regular corrugated carton boxes and shipping.
E-Flute Fine flute - about 1.2mm, 90 flutes per foot. Excellent printing surface, very compact. Usually seen in retail packaging, cosmetics or point-of-sale boxes. Not recommended for use in heavy loads.
F-Flute Ultra-fine – approximately 0.8mm. It is used to market small retail boxes where print quality and presence on shelf are more important than structural strength.
Flute selection guide:
- Fragile or heavy items → A or C flute, double-wall
- High-print-quality retail packaging → E or F flute
- Standard e-commerce shipping → C flute, single-wall
- Heavy industrial parts → B or C flute, double or triple-wall
- Food service and canned goods → B flute
Types of Corrugated Boxes (Box Styles)
Box style is the way in which the corrugated board has been cut and folded into its final form. The style you use will be determined by your product size, how you pack and seal the boxes, and if they will be used as a display box.
Regular Slotted Container (RSC) - The most popular box shape in the world. All 4 flaps are equal in length and when folded meet in the middle. Easy to machine pack, inexpensive to manufacture and can be made in almost any corrugated box size. You've probably opened a lot of e-commerce and shipping boxes that are RSCs.
Full Overlap Slotted Container (FOL) - Outward flaps completely over laps and do not meet in the middle. This adds additional supporting strength and also provides bottom to heavy items or boxes that will be on a pallet for long periods of time.
Die-Cut / Custom Boxes - Cut with steel-rule and/or rotary dies to create shapes that RSC can't. For auto-lock bottoms, custom inserts, mailer-type closures and retail packaging requiring exact dimensions. It is more expensive to set up the tooling but is cost effective when produced in volume.
Telescoping Boxes Two-piece design - a separate lid and body. Usually used for clothes, art, books, and boxes used for retail presentation where the box requires top-load access.
Mailer / Self-Seal Boxes - Pre-glued, peel and seal closure. No tape required. Lots of use in D2C for fashion, cosmetics, and subscription boxes. It is quicker to pack and has a little higher material price.
Retail Display Boxes – designed to stand on the shelf or stand on the floor display. May include perforations to create a display tray when the shipping box is separated, often use E or F flute for print quality.
Also Read:- Corrugated vs Cardboard Box - What's the Difference?
Common Uses of Corrugated Boxes
E-commerce & D2C shipping is the dominant use case. Corrugated boxes shield products across all handling locations - warehouse, carrier sortation, doorstep delivery - without the impact of margin.
Food and beverage packaging - Packaging boxes made of corrugated fiberboard are used to transport food, drink, frozen foods, and shelf-stable foods around the world every day. There are Food Grade Liners and Coatings for direct food contact use.
Electronics and fragile goods - Double-wall construction with A or C flute handles the cushioning needs of electronics, glassware and ceramics. Usually used with foam inserts or honeycomb pads to provide extra protection.
Industrial and heavy parts - Triple-wall corrugated, lighter and cheaper than wooden crates, is used in many applications as industrial and heavy parts. Applicable to vehicle components, machinery and bulk industrial materials.
Retail point-of-sale displays - Other than corrugated plastic box alternatives, paper corrugated display boxes are the most popular retail point-of-sale display solutions due to their ease of printing on, shipping light and inexpensive disposal.
Moving and storage - Household moves can be done by Moving and storage Standard RSC boxes in common sizes. Constructed to withstand commercial relocations and long storage, heavy-duty double wall models are available.
Benefits of Corrugated Packaging
The fluted medium will cushion and protect, and reduce damage. Corrugated packaging always outperforms alternatives when it comes to consistent reduction in transit damage rates when it is well specified.
Lightweight – lower shipping costs – corrugated board is primarily air (flute space). That translates to effective protection at minimal additional weight, particularly if carriers are based on dimensional or actual weight.
Customization and branding - Corrugated boxes can be custom and branded with up to 4-color flexographic or full-color digital printing. Custom sizes, shapes, coatings and die cuts are available as well at moderate quantities.
Eco-friendly and recyclable - Corrugated cardboard is recyclable and eco-friendly, and is easily accepted in curbside recycling programs around the world. High recycled content, mature repulping infrastructure, and paper packaging avoids end-of-life issues of plastics.
Cost efficient – For most shipping applications corrugated is the most cost effective protective packaging solution: cheap to produce, cheap to print on, cheap to dispose of and cheap to recycle.
How to Choose the Right Corrugated Box
The 5-step process of getting the spec right.
Step 1: Product weight — heavier products require more ECT ratings and walls. Single wall is generally OK for under 20 lbs. 20–50 lbs, consider double-wall. Double or triple-walled, depending on stacking over 50 lbs.
Step 2: Fragility Fragile products require cushioning – either larger flute profile (A or C) or additional inserts. For non-fragile dense products, smaller flutes will be used.
Step 3: Transit distance and handling - When you are shipping long distances internationally, multi-carriers or temperature variable environments, there is a greater margin in your spec. Lighter constructions can be used on short local routes with controlled handling.
Step 4: Stacking requirements - When boxes are to be palletized or stacked in storage areas, ECT rating is a factor in your selection. Double wall 5 ply at 51 ECT is able to support large stacking loads. If you do this wrong, your boxes will crush.
Step 5: Print and presentation needs - If the box is branded (retail or D2C unboxing) then you should consider using E or F flute and quality printing. For the plain brown shipper, RSC (flute) works a treat.
Common mistakes to avoid:
- Excessive specifications of walls and inadequate specifications of the box (wasted money and protection)
- Using single-wall for products that will be pallet stacked.
- Using fine flute (E/F) for heavy products to get cushioning properties.
- Forcing the use of standard sizes when custom corrugated box sizes would reduce void fill and lower dimensional weight charges.
Sustainable Corrugated Packaging
The sustainability of corrugated packaging has progressed beyond greenwashing and is now a reality.
Recycled and certified materials - Virgin fibre is a certified material Recycled and certified materials FSC (Forest Stewardship Council) certification means the use of virgin fibre from responsibly managed forests. For most uses, high recycled content liners can be used, which decreases the amount of virgin fiber used.
Water-based inks and coatings - In most corrugated mills, water-based inks and coatings are the norm today in flexographic printing. Recyclable, aqueous coatings. Avoid using UV coatings and laminations unless they are necessary as they can affect the recyclability.
Right-sizing - The most significant sustainability choice you can make is in the right sizing of corrugated boxes for your products. Oversized boxes result in higher material usage, higher void fill, and higher dimensional weight charges.
How sustainability supports business - How sustainability helps business Retailers have put sustainable packaging on their supplier agenda. Ecommerce brands leverage recycled corrugated in their brand story. In areas where corrugated is a second choice to plastics, the push to adopt it is accelerating.
Conclusion
While selecting corrugated boxes is not a difficult task, it is important to understand what factors are important in the box: wall construction is important for strength, flute type is important for cushioning and printability, box style is important to your packing operation, and sizing is important to eliminate waste.
These are done correctly and you will minimise damage, reduce shipping costs and have packaging that presents your product properly. Miss, and you spend too much on unnecessary spec or you're not adequately protecting products that arrive damaged.
Once you've identified corrugated packaging for your business, whether it's a standard RSC mailer, custom die-cut retail boxes or heavy duty double wall industrial containers, you need to request a quote for the actual product specifications.
Get in touch with our packaging team with the size, weight and volume of your product, and we will be able to suggest the most suitable construction and will provide you with a sample before placing a full order.
Frequently Asked Questions
1. What is a corrugated box?
A corrugated box is a shipping container made from corrugated paperboard - flat liner sheets on the outside with a wavy fluted layer in between. That internal flute is what gives it strength and cushioning far beyond regular cardboard.
2. What is the HSN code for corrugated boxes?
Corrugated boxes fall under HSN code 4819. This code covers cartons, boxes, cases, bags and other packing containers made of paper or paperboard. Corrugated paper or paperboard boxes are specifically classified under HSN 4819 10 10.
3. What is the GST rate on corrugated boxes in India?
The GST rate on corrugated boxes is 12 percent. This rate applies to cardboard boxes, corrugated carton boxes and corrugated fiberboard boxes. These boxes are used for packaging and shipping. They fall under HSN code 4819. Corrugated boxes are a part of shipping.
4. What factors affect corrugated sheet price?
The price of corrugated sheets depends on things. These include the type of paper and its weight, the number of layers, the type of flute and the size of the sheet. The quantity ordered also affects the price. The cost of materials, mainly kraft and recycled paper is the biggest factor. This cost changes, with paper market rates.
5. What does corrugated box design involve?
Corrugated box design involves two things. First there is the design. This includes the dimensions, wall construction, type of flute and box style. The box style can be RSC, die-cut, mailer and so on. Second there is the design. This includes printing, branding, color and finish. Both parts of the design affect the cost, protection and look of the box. The box represents your product.
6. Corrugated vs. cardboard - which is stronger?
Corrugated fiberboard is significantly stronger than cardboard (paperboard) for any load-bearing or shipping application. The fluted core in corrugated board creates a structural arch that resists compression and impact. A single-wall corrugated box typically handles far greater stacking loads than thick paperboard of comparable weight.
