Board Grades & Flute Styles: Cardboard products

We have prepared this quick & easy guide to help you understand what you need know about Cardboard strength – Board Grades and Flute Styles. Especially for those new to this space, you might be thinking a cardboard carton is a cardboard carton!

Cardboard packaging – small and large, is a popular and versatile product. From cardboard trays carrying hot beverages, protecting paint tins and domestic appliances to name a few. In some cases, businesses experience that cardboard packaging can be cost effective option, while offering the required strength and protection. And they have switched to replacing a timber box or timber pallet with a cardboard alternative!

Board Grades & Flute Styles

Here’s quick definition…

Board Grades: The grade of corrugated board is determined by factors such as the weight and type of outer liner, flute type, and weight and type of inner liner.

Flute Styles: Corrugated box fluting is available in various sizes and types, each suitable for specific purposes. Generally, larger flutes such as A and B profiles offer enhanced strength and cushioning, while smaller flutes like D and E profiles provide improved printability and foldability.

board grades Cardboard Boxes
board grades Cardboard boxes
board grades Cardboard boxes

Board Grades

The Gilmores team will work with you to determine the necessary strength of the fluted material for a corrugated cardboard container.

As “Cardboard Engineers,” we can design a package to meet your needs. We provide a variety of strong, eco-friendly cardboard packaging options.

Several factors determine the strength and cushioning performance of a corrugated box.

These include the:

  • box size,
  • shape
  • style
  • board grade
  • flute profile

These elements greatly impact the level of protection provided by the carton. We have a variety of standard board grades and flute profiles to choose from, allowing you to select the ones that best suit your product.


  • Long Fibre = high tensile strength, high tear resistance, durable option.

  • Enhancement of strength is achieved by the combination of virgin Fibre / long Fibre properties under high humidity conditions and when stacking strength is required.

  • Mostly ideal for frozen / refrigerated products, heavy duty packaging and dangerous goods.


  • Short Fibre = Offers acceptable stacking strength in “dry” conditions.

  • Many products do not require full Kraft liners.

  • Many different recycled paper options & we use a high proportion of recycled paper

  • Almost all corrugating medium is recycled.

Flute Styles

Fluted sheets are used to create the final product, and are made by laminating different types and grades of paper together in various combinations.

E Flute:

E Flute is commonly used for inner packaging, where compression strength and cushioning are not important. It has minimal crush, making it easy to die-cut. It is often used for lithographic (litho) laminated fluted cartons, such as lithographic mobile phone cartons and the McDonald’s 4 Cup tray.

Cardboard Cartons Board Grades

B Flute:

This type of packaging is typically utilised in situations where the priority is maximizing space and containing items, rather than providing strong stacking capabilities. It is commonly seen in beer boxes, cans of soda, and paint cans.


C Flute:

This material is typically used when there is a need for strong compression strength and cushioning for the contents. It is particularly beneficial in situations where the primary packaging and contents do not add much or any support to the overall stacking strength of the outer packaging.


Cardboard Cartons Flute Styles

Twin Cushion:

This material is primarily used for heavy duty packaging and big boxes in special applications –  requiring high performance in stacking strength and cushioning.

Different flute profiles can be combined to create various types of twin cushion material, with the board strength characteristics determined by the material thickness and paper quality.

Twin Cushion Combinations:

  • Twin Cushion B/E 4mm – Produce medical boxes, trays.

  • Twin Cushion B/C 7.5mm – Commonly double wall board; Big boxes, Electrical Products.

  • Twin Cushion A/C 10mm – Domestic Appliances (washing machines, refrigerators), Water heaters.

  • Twin Cushion A/A 12mm –  Heavy duty packaging applications. Has High Puncture resistance.

  • Twin Cushion A/A/C 16mm – Triwall Flagship Board for the corrugated box industry. Used for products that require sturdy cartons for optimal stacking and protection and shipped internationally. A great alternative to using timber –  ISPM 15 Compliant.

Cardboard Boxes Board Grades
Cardboard Cartons Board Grades
Cardboard Cartons Board Grades


  • Styles Selected Based On Application

  • White & Brown Board Available

  • Single, Double & Tri Walls

Next Steps?

After reading over the guide, it’s fair to say that there’s more involved to a Cardboard Carton. We hope you can use this information to help you acquire the right Cardboard packaging for your business.

The Gilmores team have been supporting a range of businesses and different protect types with their Cardboard Cartons requirements – ensuring the Cardboard Carton offers the required strength and protection. Our experienced Cardboard Engineers work directly with customers should they have specific custom requirements.

We have on hand at our facilities,  standard Cardboard Cartons available for quick and short turnaround orders. Plus being a Single Source Packaging Supplier, our customers benefit from the convenience, our networks and our experience supporting a range of industries and businesses.

Get in touch with our experienced team to discuss your overall Cardboard Cartons & Cardboard requirements.