When you look at a corrugated carton, you will notice that it’s made of more than just flat cardboard. Inside the layers, there are wavy paper sheets called corrugated flutes. These flutes play a very important role, they give the box strength, protect the items inside, and help the box stay in shape during shipping or handling.

Each flute has a different thickness and strength level. The common types used in packaging are A, B, C, E, and F. Every type serves a different purpose depending on whether you need strong protection, good print quality, or a lightweight design. Understanding these flutes helps you choose the right carton box for your product.

Different Wall Structures of Corrugated Boxes

Corrugated boxes are not all made the same. Their strength also depends on how many layers they have. Here are the basic types:

Single Face (2 Ply):
One corrugated medium is glued to a single flat sheet of linerboard. This construction offers cushioning but no backing on the opposite side.

Single Wall (3 Ply / Double Face):
Also called Double Face, this is the most common type where the corrugated medium is glued between two sheets of linerboard, providing good strength and protection.

Double Wall (5 Ply):
Made with three sheets of linerboard and two corrugated mediums, this type offers extra durability and is often used for heavier or bulkier products. Moreover, it provides reliable protection during shipping and handling.

Triple Wall (7 Ply):
It features four sheets of linerboard and three corrugated mediums, providing maximum strength for very heavy or industrial packaging needs.

Types of flutes in corrugated boxes

In corrugated packaging, the flutes A, B, C, E, and F flutes offer distinct characteristics that influence the box’s strength, thickness, and functionality.

A-flute

A-flute is the thickest and most substantial type of corrugated flute, featuring approximately 33 flutes per foot and a thickness of around 4.8–5 mm. Therefore, its wider, more pronounced arches provide excellent cushioning, making it ideal for protecting fragile or heavy products that require additional shock absorption.

Recommended For

  • Large shipping boxes
  • Appliance boxes
  • Cardboard packing boxes

B-flute

B-flute features around 47–50 flutes per foot and has a thickness of about 2.5–3.2 mm, making it thinner yet more rigid than A-flute. Its tighter, denser structure provides better puncture resistance and a smoother surface for printing. Many industries widely use it for transport packaging and retail applications.

Recommended For

  • Food and snack boxes
  • Cosmetic boxes
  • Pharma boxes

C-flute

Corrugated packaging commonly uses C-flute, which offers 39–43 flutes per foot and measures 3.5–4 mm in thickness. It provides excellent stacking strength and good crush resistance, making it suitable for both transport and display.

Recommended For

  • Shipping boxes
  • Fruit boxes
  • Retail boxes

E-Flute
E-flute is a thinner option featuring 90–96 flutes per foot and a thickness of about 1.2–2 mm. It offers a smooth surface perfect for high-resolution printing while still maintaining good crush strength. Its compactness makes it ideal for premium and space-efficient packaging.

Recommended For

  • Electronics boxes
  • E-commerce boxes
  • Luxury packaging

F-flute
F-flute is the narrowest variety of corrugated flute, measuring approximately 0.8mm in thickness and containing roughly 125–130 flutes per foot. Moreover, it provides a highly smooth surface; therefore, it is ideal for intricate printing, precise die-cutting, and premium retail packaging. In addition, manufacturers frequently choose F-flute for sturdy and compact packaging solutions such as tuck-end boxes, cosmetic packaging, and point-of-purchase displays, where both design appeal and structural strength are equally important.

Recommended For

  • Premium cosmetic boxes
  • Tuck-end boxes
  • Point-of-purchase displays

How to Choose the Right Flute

You should select the flute type based on:

✔ Product Weight

  • Heavy or fragile items → A or C flute
  • Medium-weight products → B or C flute
  • Lightweight retail items → E or F flute

✔ Stacking & Shipping Conditions

  • Long-distance shipping → C or Double Wall (5 Ply)
  • Heavy stacking → C flute or 5 Ply combination

✔ Printing & Branding Needs

  • High-quality printing → E or F flute
  • Standard branding → B flute

✔ Space Optimization

  • Compact packaging → E or F flute
  • Cushioning priority → A flute

What Roshan Packages Offers

Roshan Packages Limited, along with its subsidiary Roshpack, is one of the leading packaging companies in Pakistan, offering innovative and high-quality solutions for both industrial and retail packaging. From durable corrugated cartons to customized designs, they provide comprehensive services for businesses looking for reliable protection and supply chain efficiency.

They offer a comprehensive range of corrugated packaging solutions designed to meet diverse industrial and retail requirements. The company provides 2 Ply (Single Face) single facer sheet rolls available in B Flute, C Flute, and E Flute, suitable for cushioning and wrapping applications. For stronger packaging needs, 3 Ply (Single Wall) sheets and boxes are available in B Flute, C Flute, and E Flute, delivering reliable strength and product protection for standard shipping and retail use. Furthermore, for heavier and bulk packaging requirements, 5 Ply (Double Wall) sheets and boxes are offered in combined flute structures including B + C Flute, B + E Flute, and C + E Flute; as a result, they provide enhanced durability, improved stacking strength, and superior protection during transportation and handling.

From durable corrugated boxes to customized packaging solutions, the group is committed to enhancing product protection and supply chain efficiency.

If you’re looking for a packaging shop near me or expert advice on selecting the right corrugated structure, Roshan Packages Limited is your go-to solution. Contact them at 03236-767426 for tailored packaging solutions.