It either seems like a no-brainer or like an overwhelming task when deciding what corrugated shipping boxes suite your products. Not to worry, we are here to help! If you have experience in the packaging industry, you might already know the basics. For those who are new, unsure, or just want a refresher, here's a simple guide to some of the most commonly used corrugated. 

First off, corrugated fiberboard also known as paperboard (often mistakenly referred to as cardboard) is made by gluing a flat layer/sheet of fiberboard to a corrugated (wavy) layer. The wavy layer is known as "fluting" with each wave being known as "flute". The fluting (wavy layer) provides cushioning, rigidity, and support; therefore, making corrugated boxes great for shipping and packaging!

To keep it simple and to the point, let’s focus on the most common types of corrugated packaging.

Single Face Board - is very inexpensive to produce, is not as durable as other corrugated products, but can provide an extra layer of protection inside packaging; for example, wrapped around a wine bottle that is then packaged in a corrugated box for shipment.

Single Wall - Also known as "standard corrugated or double face", is two sheets of fiberboard with one layer of fluting in between. This is the most commonly manufactured style of fiberboard. This can be used for boxes or for an extra sheet layer of padding for weight disbursement.

Double Wall - is basically a single wall glued to a single face creating a much more resistant packaging material adequate for stacking or for heavier objects. This type of corrugated is commonly used for larger industrial containers.

Wait, what was that about flutes and fluting?

Don’t worry. We’ve got you. It’s really not that complicated.

Remember the wavy layer of fiberboard is known as fluting and each wave in that layer is called a flute. So, flute is the space between fiberboard layers, and there are different variants of flute (spacing in the wavy layer). In terms of packaging, flute type describes how thick the walls of a certain box are. Flute type affects the box in regards to durability, stacking resistance, or suiting to a certain kind of product.

Let’s cover some basic corrugated box fluting information.

Two common flutes for single wall boards are:

C - Flute - 39-43 flutes per foot with 5/32″ thickness. It is by far the most common type of fluting because of its versatility. It’s a fairly good surface to print on and is strong enough for most shipping situations including, but not limited to, glass, furniture, and dairy. It offers greater compression strength than ‘B’ flute; thus, giving slightly better stacking strength for lighter products as long as it is not misused.

B-Flute - 42-50 flutes per foot with 1/8″ thickness. It’s better for folding into intricate shapes and for printing, so this is the flute commonly seen for Point-of-Purchase (P.O.P.) displays or for cardboard cutouts. It is also commonly used for smaller products and boxes.

Two common flutes for single wall boards are:

B/C - Fluting - 1/4th of an inch in thickness and is double wall material that joins two flute profiles together – ‘B’ and ‘C’, both of which give excellent all round performances individually and more so together. This kind of fluting is most often seen in shipping cases where a high level of protection is required such as for larger industrial containers or heavier objects.

Flute TypesFlutes/FootThicknessAdvantages
B Flute 42-50 1/8" Good cushioning, stacking & printing
C Flute 39-43 11/64" Good stacking, strength & crushing resistance
BC Flute Double Wall Very Thick Can hold very large & heavy items

So...when do you use what box?

Consider - Board Strength, Box Strength, & Measurements

Board strength is flute size and the number of box walls (single wall, double wall, etc.) which determines the box strength once assembled. There are two industry standards for testing and certifying corrugated box strength.

The Mullen Test (Burst Test) determines how much pressure a wall board can withstand from internal forces or external forces before being punctured or bursting; therefore, measuring the wall strength of a box. This is especially useful to know if you’re packing oddly-shaped objects that would put pressure on small spots in which case, you might want to ship said objects in a Mullen-rated box.

The Edge Crush Test (ECT) determines how much pressure a box can handle before being crushed or buckling. This test is commonly used since most boxes are stacked up for shipping and warehousing. ECT certified boxes use less material than Mullen Test (Burst Test) boxes. Less material means these corrugated boxes are less expensive to produce and can be lighter in weight, yet adequate for most consumers’ uses when they don’t necessarily need one test or the other.

When choosing board strength consider what will be packed in the box, the total weight of the box including its contents, the inner and outer dimensions of the box, and how you’re planning to stack and ship it. Some of this information can be found on the Box Maker’s certificate normally printed on the bottom of each box.

When in doubt, check the Box Maker’s Certificate

A Box Maker’s Certificate (BMC) is a seal usually printed on the bottom of a box that tells you some specifications including how strong it is. Depending on whether the box is Mullen Test (Burst Test) certified or ECT certified, the seal will vary slightly.

Both styles of seal will contain some of the same basic information. You should primarily look at Board Construction (single wall, double wall), Size Limit (total sum of box outer dimensions), Gross Weight Limit (maximum allowable weight of box including contents), and Bursting Test rating (box wall strength before puncturing) or Edge Crush Test (compression strength of the box walls). If you refer to the BMC seal, you’ll have all the information you need to make the right choice for your product’s shipping and storage needs as long as you already know your product specifications beforehand.

You've got corrugated basics down!

Now that you’re familiar with the basics of corrugated paperboard, you’ll probably stick to just a handful of corrugated box types for your packaging and shipping needs due to cost, availability, and performance ratios. Hopefully, you feel more confident in your decision making and in your corrugated packaging selections. Here at TOTALPACK we are totally committed to helping you find solutions. Whether you’re an industry newcomer or a seasoned pro, we are here to help!

Reach out to us! We’d love to learn more about your specific needs and help you find the best packaging for your products. We’ve also got many other affordably priced goodies you should check out.

If you’d like to download our catalogue and stay in the know, just fill out this form!