Not all corrugated boxes are created equal. A wrong choice can mean damaged goods, wasted materials, and mounting expenses. For more than 65 years, Shipmaster Containers Limited has been helping businesses find the right packaging for their needs. This blog post covers board construction, flute sizes, and box styles to ensure that you make a more informed packaging decision.
What Is a Corrugated Board?
Corrugated board is an engineered material made up of a wavy inner layer, called the flute, sandwiched between two flat outer liner sheets. The wave-shaped core is what contributes to its remarkable strength, cushioning, and stackability. The number of layers and the shape of those waves determine how the final box performs under real-world shipping and storage conditions.
Board Construction Types
Single Face Sheet: One linerboard pressed to a single corrugated medium, available both in sheets and rolls, and used for wrapping or as an interior cushioning material, but not as a container.
Single Wall (Double Face): The most common and versatile construction is a 3-ply board in which the linerboards are bonded to both sides of the corrugated medium. It covers a wide range of strengths and flute sizes, suitable for e-commerce shipping cartons to retail display boxes.
Double Wall: A 5-ply construction board made with two corrugated mediums on the inside, and linerboards in between, such as B and C flutes. It offers extra rigidity, padding, and stacking strength and is ideal for heavier products that require additional protection during shipping and storage.
Triple Wall: A 7-ply construction with three corrugated mediums and four linerboard facings (usually C+C+B flutes). They are especially designed for larger-capacity containers, such as pallet packs, and offer the highest crush resistance, making them a sustainable alternative to wooden crates for heavy-duty industrial shipments.
Corrugated Flute Sizes Explained
The flute profile is the most important characteristic which determines the performance of corrugated boards. It affects cushioning, stacking strength, printability, and overall thickness. Here’s how each profile compares, from largest to smallest:
A-Flute (32-37 flutes/ft | ~1/4″ thick): The thickest and original corrugated profile. Its tall, widely spaced arches trap more air between the liners, delivering exceptional cushioning and the best stacking performance of any single-wall board. It also possesses excellent short-column crush resistance. Best for fragile or heavy goods that require superior protection throughout the supply chain.
B-Flute (45-52 flutes/ft | ~1/8″ thick): This is thinner than A-Flute, but has more flutes per foot, creating a stiffer, flatter surface that’s ideal for high-quality printing. It is also very dense and provides outstanding crush and puncture resistance. Suitable for retail packaging and die-cut applications where durability and sharp presentation matter.
C-Flute (39-43 flutes/ft | ~3/16″ thick): Considered the industry standard. C-Flute offers an optimal balance of cushioning, stackability, and printability at an affordable price, and is the most widely used flute in everyday shipping cartons. It also forms the base of double-wall (B+C) and triple-wall (C+C+B) constructions.
E-Flute (92-98 flutes/ft | ~1/16″ thick): A very fine wave profile with a very smooth, flat surface and is exceptionally suitable for high-resolution printing. E-Flute has approximately one-quarter the thickness of A-Flute and significantly lowers the dimensional shipping weight, saving valuable storage space. It has a very compact design while providing high crush resistance. Perfect for high-end retail, cosmetic, and food packaging.
F-Flute (128 flutes/ft | ~1/32″ thick): The thinnest and newest corrugated packaging innovation, which originated in Europe and is the fastest-growing segment of the packaging industry. F-Flute creates rigid, lightweight boxes, using less material, less weight and a smaller environmental footprint. Ideal for small consumer goods, electronics accessories and brands with sustainability commitments.
Common Corrugated Box Styles
Regular Slotted Carton (RSC): This is the most common shipping carton in use today. Simple, strong and extremely economical, made from a single blank with top and bottom flaps that meet at the middle of the box width.
Full Overlap Slotted Carton: Outer flaps overlap the full width of the carton when folded, providing additional moisture protection and reinforcing the bottom panel.
Half Slotted Carton (HSC): Flaps are only on one side of the carton, typically with a separate lid. Great for shelf storage boxes, bulk pallet use, and where the contents need to be readily accessible and displayed.
Telescope Carton: A two-piece construction, body and cover that telescope each other. Ideal for custom depths and products that are regularly packed and unpacked.
Die Cut Boxes: Custom structural designs with self-locking tabs, carry handles, display cutouts, and irregular contours produced with a steel rule die press. Many die-cut designs do not require any tape, stitches, or glue to assemble and close. Please note that there is typically a one-time cost for the steel rule die.
Point-of-Purchase Displays: Specially designed for counter and floor displays to showcase merchandise products in-store while maintaining the structural integrity needed to perform throughout the retail cycle. Shipmaster designs and manufactures all-in-one display systems from shelf to base.
How to Choose the Right Box
To guide your choice, here are a few key questions to consider:
- What are you shipping, and how fragile is it?
- How many handling points will the box go through?
- Does the packaging need to perform on-shelf and also during transit?
A-Flute is the right flute size for heavy and fragile products. B, E or F-Flute is ideal for retail packaging. C-Flute RSC boxes are most economical for high-volume shipping. When the answer isn’t obvious, Shipmaster’s team can help engineer the right solution for you.
Need our guidance in finding the right corrugated solution for your business? Request a callback or dial (416) 493-9193.
FAQs
1. What is the most common corrugated flute size?
C-Flute is the industry standard. It balances cushioning, stacking strength, and printability at a cost-effective price point and is used in most everyday shipping cartons across virtually every industry.
2. What’s the difference between single-wall and double-wall corrugated?
Single wall is a 3-ply board suited to most general shipping needs. Double wall is a 5-ply construction combining B and C flutes, offering significantly more rigidity and strength for heavier or more fragile products.
3. Which flute is best for retail packaging with high-quality printing?
Both B-Flute and E-Flute provide a flat and smooth surface that is suitable for sharp and high-resolution printing. E Flute is recommended where a slimmer profile and high-end presentation on the shelf is the priority.
4. Is corrugated packaging environmentally friendly?
Yes. Corrugated is produced from a renewable resource and can be recycled in Canada at rates of almost 100%. E Flute and F-Flute profiles are thinner and use less fibre, helping to lower the environmental impact without affecting performance.
5. How long does it take to order custom corrugated boxes from Shipmaster?
Standard plain kraft box orders will ship within 5–10 business days. The manufacturing time for a first-time custom-made box that requires a steel or print die is approximately 2–3 weeks, depending on the complexity of the design, print and structural needs.
6. Can Shipmaster handle large-volume orders and ship across Canada?
Absolutely. Shipmaster has extensive manufacturing capabilities to fulfill orders of any size, with supply chain solutions to deliver corrugated packaging to businesses nationwide across Canada.
