The Ultimate Cardboard Thickness Guide: How to Measure Weight, Thickness, and More

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The gamut of packaging solutions on the market is ever-increasing. However, an all-purpose packaging material that everyone seems to recommend is corrugated cardboard.

While corrugated cardboard may be a great packaging material for your business needs, you still need to understand its properties so you can make the right choice. There are many different types of corrugated sheets that vary in thickness, durability, and performance capabilities.

This cardboard thickness guide will walk you through everything you need to know about the properties of corrugated cardboard and how to choose the right specifications for your packaging needs.

Let’s get started!

What is corrugated cardboard?

Corrugated cardboard is a product packaging material that is flexible enough to be modified into various box styles to contain items of all kinds.

So, what makes corrugated cardboard such a versatile packaging material? Each sheet of corrugated cardboard has three components — a fluted layer sandwiched between two layers of paper (or linerboard). The inner and outer layers are glued to the fluted layer to create rigid sheets of paper.

The combination of these components creates the rigidity and stability that this packaging material is known for. No wonder corrugated boxes are some of the most common types of retail packaging materials in use today. What’s more, these boxes can be made to be much stronger.

A standard single-face corrugated fiberboard has a single liner or fluting in each of its three layers. This type of cardboard is called a single-wall board. A box like this can hold items up to 20 lbs in weight.

When the liners and fluting are doubled, you get a double-wall board. The additional reinforcement provides the strength to hold heavier items. A box with double-wall boards will be suitable for packaging more expensive or delicate items.

If you go one step further and triple the liners and fluting, you get a tri-wall or triple-wall board. With this, you get sheets that can hold weights of up to 300 lbs. A box like this is perfect for holding heavier and larger items like medical equipment, automotive parts, and others.

The benefits of corrugated packaging

Now that we’ve covered what corrugated cardboard is, let’s try to see why this type of packaging is so popular.

1. Protection

Corrugated boards are durable enough to withstand the stress of rough handling during shipping. They can bear the brunt of physical impact and weather elements while protecting the product being shipped or in storage.

2. Weight

Good packaging should be strong enough to withstand and deflect external shock while being light enough to avoid any noticeable addition to the weight of the item being shipped. Corrugated packaging is not only lightweight but also rigid. It is firm but doesn't bulk up your package.

3. Branding

Corrugated boards are excellent platforms for printing. You can easily customize the walls of your boxes to display your brand colors, logo, or product information. This is applicable to all types of board grades and thicknesses.

4. Sustainability

Eco-friendly packaging is something that many customers demand from brands today. Corrugated boxes are perfect examples of sustainable packaging. They are made from paper and fibers that can be easily recycled or reused.

Corrugated boxes vs cardboard boxes: What’s the difference?

Most people believe a cardboard box and a corrugated cardboard box to be one and the same. However, this is wrong because they are made from different materials. Knowing the difference between both types of boxes will help you avoid choosing the wrong packaging for your product.

Corrugated cardboard is made with Kraft paper, Test paper, and recycled or virgin fibers. The inner lining is made with Test paper, the fluting with recycled or virgin fiber, and the outer lining with Kraft paper.

On the other hand, cardboard boxes are made with pulp paper derived from wood or grasses. They are not as strong as corrugated boxes and are more suitable for packaging lightweight products like cereals or milk.

Cardboard thickness: Why does it matter?

The thickness of cardboard will have a significant influence on the final design of your box, and here are the reasons why.

1. Product Type

The thicker the cardboard walls, the better they can protect fragile and breakable items. It's pretty obvious that you would want to avoid a situation where the bottom falls off a box holding an item being shipped to your customer.

2. Shipping

Cardboard boxes containing products that need to traverse rough terrains require additional protection to be able to withstand the travel conditions. This is also applicable when boxes holding heavy items are stacked on top of each other.

3. Costs

Thicker corrugated cardboard boxes are not cheap. You will have to pay for the added protection. The extra thickness also makes the box wider and heavier, which means higher shipping costs.

4. Printing

Cardboard thickness impacts the quality of printing. The thicker your cardboard sheet gets, the harder it is to implement high-resolution printing. Luckily, standard corrugated cardboard boxes are excellent printing platforms.

Corrugated cardboard properties

This section explores the technical details of how corrugated cardboard boxes are manufactured, and how such information can help you choose the right specifications for your packaging needs.

Flutes

The fiber used to make flutes can be either Semi-Chem (SC) or Waste-Based.

Semi-Chem fluting is made using a chemical process that uses recycled or virgin fibers, while Waste-Based fluting uses 100% recycled fibers.

There can be several flute profiles based on the thickness of the fiber. Popular flute sizes include:

• A-Flute: 5mm thickness
• B-Flute: 3mm thickness
• C-Flute: 4mm thickness
• D-Flute: 2mm thickness
• E-Flute: 1.5mm thickness
• F-Flute: 0.6 to 1mm thickness
• BC-Flute: 6mm thickness
• EB-Flute: 4.5mm thickness

There are other options, but this list contains the types of flutes most often used for packaging. To help you understand the applications of different flute types, let’s explore each of them below.

A-Flute

This is the thickest single-wall fluting material. It offers the highest protection and the best cushioning properties. Its ¼-inch thickness ensures it has excellent crush resistance and stacking strength — a desirable feature in boxes that will be stacked for extended periods of time. A-Flute is often used in boxes made for packaging fragile items.

B-Flute

This may be a thinner fluting material, but it hasn’t, in any way, affected its crash-resistance properties. B-Flute’s flatter surface area means it consumes less space. Its thinness also makes it excellent for printing. You can use it in counter display boxes, i.e. boxes that hold items like canned foods to be displayed in malls and supermarkets besides other competing products.

C-Flute

Arguably this has the most perfect thickness, which makes it the most popular flute type by a wide margin. Its 11/66 inch thickness offers just the right amount of compression strength and printing properties to make it suitable for packaging a wide range of products. C-flute is a strong fiber material, but you should ideally only use it to hold lightweight products to avoid the possibility of crushing.

E-Flute

This is a thin fiber material with much lower stacking and compression strength. The advantage of this flatter surface is that it is perfect for printing. A reduced surface area also means it helps you save on storage space. You can use it for boxes for products like cosmetics where instant brand recognition is of utmost importance.

The following products from noissue are all made from E-flute corrugate:

• Custom Mailer/Shipping Boxes - Home compostable or curb-side recyclable
• Custom Gift Boxes - Home compostable or curb-side recyclable
• Custom Container Shipping Boxes - Recyclable
• Custom Candle Boxes - Recyclable
• Custom Reverse Tuck End Boxes - Recyclable
• Custom Straight Tuck End Boxes - Recyclable
• Custom Shoe Boxes - Recyclable
• Stock Kraft Boxes - Home compostable or curb-side recyclable
• Custom Wine Carriers - Recyclable

F-Flute

This is an even finer flute material than E-Flute. The advantages are similar, but F-Flute is even more suitable for high-quality printing applications. This flute type is popularly used in clamshell packaging.

BC-Flute

This is a combination of the B and C flutes to create a 6mm thick fluting material. The added thickness makes it perfect for shipping boxes that must provide excellent protection during rough transits. It is also a great choice for boxes built to hold heavy items.

EB-Flute

Yet another double-wall fluting material that combines the E and B flutes to create a board that is both durable and suitable for printing. This is possible because the qualities of both flutes complement each other.

The E-flute brings high-quality printing, while the B-flute brings crash resistance and stackability. The flute type is suitable for holding a wide range of items and is an ideal choice for business owners looking for a box that offers excellent protection and customization.

Outer and inner liners

The outer liner is typically made of Kraft paper. Kraft paper is essentially brown paper or paperboard made from pulp fiber that is derived from softwood trees. It’s very stiff and durable. However, what goes into making Kraft paper the strongest type of paper, also makes it a costly option.

The most popular Kraft paper grades are:

• Brown/Virgin Kraft paper: It’s very strong and has excellent puncture resistance. It can also have a different color other than brown, depending on the pulping process used.
• White Top Kraft: It’s also strong, but much more affordable. It offers an excellent printing surface.
• Mottled/Oyster Kraft: It has an off-white color with a mottled appearance. It is the most sustainable option because of its high recycled content. However, it only offers medium-quality printing.
• White Bleached Kraft paper: It has a natural white color that is achieved by treating the paper with sulphuric acid. It is a much less sustainable option.

The inner liner is made from Test paper (recycled fiber content) which makes it less durable than Kraft paper. The recycled liner is also less costly than Kraft paper.

Available Test paper grades are:

• Test 2: Partly recycled paper
• Test 3: Fully recycled paper
• White Top: Recycled paper, coated white
• Oyster: White recycled paper with a mottled appearance

Common cardboard paper weights

The unit of measurement used to weigh paper is grams per square meter or GSM.

The most popular paper weights used for the outer and inner linings are:

• 115/125 GSM
• 140/150 GSM
• 185/200 GSM
• 300 GSM

The most popular paper weights for flutes are:

• 90 GSM WBF
• 105 GSM WBF (the most common flute paper weight)
• 112 SC and WBF
• 150 SC and WBF
• 175 SC and F

Note: SC means semi-chemical fluting, while WBF means water-based fluting.

Cardboard naming

Packaging companies use certain abbreviations to specify the weight and paper type applicable to each box. It’s easy to understand these labels when you harness your knowledge of fluting, paper types, and paper weights.

For example, the label on a box may say it has a 200K/B/200T paper grade. This simply means:

• 200K - 200GSM Kraft paper
• B - B-Flute type
• 200T - 200GSM Test paper

How to measure cardboard thickness

The PT (point system) is another way of measuring cardboard thickness. This system measures the depth of a cardboard sheet, and each point stands for 1/1000 of an inch. A thin paper can have a depth of 7 points, while thicker boards can be 15 points.

Another measurement system in the industry is box strength. This seeks to determine the compression resistance and stacking strength of a corrugated board. The Edge Crush Test measures compression resistance, and the resulting value is reported in ECT ratings. 32 ECT is the most common standard.

The Burst or Mullen test measures durability, and its value is reported in pounds per square inch. 200 pounds is the most popular standard.

How to choose the right corrugated box for your needs

Consider the following when evaluating your options:

• The size and fragility of your products: Standard boxes can be used for most products, but fragile items must be packed in thicker boxes.
• The mode of product delivery: Go for a regular box if you sell your products through a brick-and-mortar outlet where customers walk in to make purchases, but opt for a more durable box if you use logistics companies to get your products to customers.
• Your branding requirements: Cardboards that support high-quality printing are best for products that rely on superior counter display, but businesses that ship heavier items should go for something more durable.
• Your budget: Research the unit cost plus the projected shipping cost of each packaging option, and select the one that you can afford and still be happy with.

You should only buy your packaging materials from a provider that meets the required standards.

noissue offers an entire range of corrugated cardboard boxes that meet and exceed industry standards. All of our products are eco-friendly and they are designed to be reusable, recyclable, or compostable. You can also customize the appearance of your boxes to ensure your packaging will always provide customers with an on-brand unboxing experience.

🎁 Wrapping it up

Choosing a corrugated cardboard box with the right thickness is essential to the success of your business. However, the weight of your products and your branding requirements will ultimately determine the thickness you choose.

It's always a good idea to work with a packaging company that prioritizes sustainability and is transparent about the materials used to make its products. noissue is that kind of packaging provider.

Check out our extensive range of packaging products that are designed to meet the unique requirements of every business!