What is corrugated cardboard? The Definitive Guide

Who invented corrugated cardboard?

The corrugated cardboard box was first invented in 1890 by the Scottish-born, Robert Gair. Gair made his discovery by accident while making paper bags. He found that through cutting and creasing the paperboard he worked with in a single operation he could create prefabricated boxes.

Since then the corrugated cardboard box has gone on to become one if not the most popular form of packaging. We see them all the time, from pizza boxes and the cardboard postal boxes we get our online deliveries in, to the cardboard removal boxes we use when moving house.

How is corrugated cardboard made?

Corrugated cardboard is created using a number of papers and the strength of the cardboard is very much dependent on the materials used. A standard sheet of corrugated cardboard is made with two main components: liner board and corrugated fluted paper. The sheet of fluted paper is sandwiched between the outside and inner liner which is then glued to the flat liner paper with starch.

Why is corrugated cardboard used for packaging?

Corrugated cardboard has become the most popular form of packaging for e-commerce companies with Amazon delivering an incredible 1.5 billion cardboard packages in 2020. So what are the advantages of corrugated cardboard that make it the top choice for packaging?

1. Corrugated cardboard is lightweight

Corrugated cardboard is light, and rigid and can provide suitable protection through shock absorption and temperature protection, which is why people are looking at utilising corrugated board in their packaging materials.

2. Corrugated cardboard offers great protection

Cardboard is incredibly effective for protecting both fragile and nonfragile items. The sheets of paper glued to the corrugated inner of the sheet give the box structure additional strength to support heavy weights, and resist shock, impact, dropping and vibration. Protective corrugated layers in cardboard also provide excellent thermal insulation and help to keep moisture away from products.

3. Corrugated cardboard can be easily customised

Corrugated packaging can improve your brand’s visibility and can work as a new channel for your product marketing. Adding printed artwork to your cardboard’s surface can drastically increase brand awareness and communicate your messages and brand values really effectively.

4. Corrugated cardboard makes for eco-friendly packaging

Corrugated cardboard makes for eco-friendly packaging and is easy to dispose of. In fact, more than 80% of corrugated packaging and boxes in the UK are recycled, a higher rate than for any other major packaging material. At Boxed-Up, our cardboard waste is recycled using a circular recycling model. Reduce, reuse and recycle is at the heart of each stage of our manufacturing process, meaning that our cardboard offcuts and waste are used again and again in our products whilst still maintaining durability!  Such effective recycling enables a renewable resource – paper fibre – to be used again, as part of a closed-loop recycling process for corrugated packaging.

5. Corrugated cardboard is flexible

Cardboard is a flexible material and corrugated material in particular is recognised for it’s premium quality and innovative structure. Cardboard provides a cost-effective and practical way to protect products, stabilise loads and box up awkwardly shaped goods. Because of its flexibility, boxes can be manufactured in a huge array of sizes and styles, combining either single or double-wall protection for your products.

Corrugated Cardboard Properties

When searching for corrugated cardboard you will generally see a description of the board as B125KT, which is a shorthand description of the board grade, paper weight and fluting size.

B = fluting Size

125 = Paper weight

KT = Kraft/ Test Paper (Outer/ Inner Liner)

To understand this further we shall look into what this means.

Corrugated Cardboard is manufactured from three components, which include one ‘fluted’ or ‘squiggly’ middle section and two outer liners of paper or card, which are then glued to the flute to add stability to the board and to create a robust structure. The liner paper is made from either Kraft or Test paper.

Kraft or Test Paper – Kraft is a popular choice when making boxes and has a smoother surface, making it an ideal choice to print on. The test is a recycled paper, it’s not as nice looking as Kraft and is often used for the inside of the boxes.

There are other types of paper such as Clay Coated and Bleached but these are more specialty papers and are not widely used in the e-commerce sector.

Paper Weight – The weight of the paper is measured in grams per square meter or GSM. Common weights that boxed-up use is 125 gsm, 150 gsm and 200 gsm.

Corrugated Board – Various types of cardboard can be created using different flute sizes, which include double wall, single wall and tri-wall. A single wall consists of two pieces of paper with one middle flute section, a double wall features an additional liner and fluting, whereas a tri-wall adds another layer of fluting and extra lining. Read our complete guide if you want to learn more about the difference between single and double wall cardboard boxes.

The flute can vary in width and size and the arch shape of the fluting allows air to circulate which acts as an insulator, providing additional protection against temperature variation. It is the flute that can affect the performance of your boxes.

  • E Flute is used on our die-cut pip boxes, such as our C4 and C5 and for smaller cartons such as our sub boxes. This type of flute is ideal for printing due to its high-quality surface, excellent compression strength and great resistance to crushing.
  • B Flute is an ideal flute for transit packaging. It is thicker and weighs heavier. This is the flute that Boxed-Up used to manufacture and is a good all-rounder.
  • BC Flute – B Flute is married with C Flute which gives a higher level of protection for your products. Boxed-Up uses this fluting profile on all our double wall boxes including our house moving boxes.
  • Z Flute – Also known as M, S, or R Flute®. It is ideal for printing due to its high-quality surface. It’s a much smaller and more compact fluting, whilst still optimising board strength. It’s perfect for e-commerce, and online sellers and offers the necessary protection for your products.

The benefits of Z-flute are as follows:

  • Bigger savings for customers
  • Neater looking boxes
  • 20% increased storage & delivery
  • More on a pallet**
  • 100% recyclable
  • Higher resistance to crushing than B-flute
  • Able to withstand the rigours of shipping
  • Perfect for the e-commerce sector
  • Reduced carbon footprint
  • Improved performance
  • No compromise to the integrity of the box
  • Ideal for FMCG

Where to buy corrugated cardboard boxes?

If you’re looking to buy corrugated cardboard boxes for yourself or your business we have a wide range of different box options including –