Why We’ve Moved from C Flute to B Flute Cardboard
1st May 2025
We’ve transitioned our single wall boxes from 4 mm C Flute to 3 mm B Flute so we can keep quality high, maintain fair pricing, and ensure a reliable supply for every order.
1) Keeping Prices Stable for Our Customers
Over the past 12 months, the cost of corrugated board has risen by around 20%. This is due to a combination of factors including shortages in raw materials, rising energy costs, and higher labour costs across the supply chain. With further increases expected in 2025, switching to B Flute helps us keep our prices as competitive as possible without compromising on quality or service.
2) Ensuring a Reliable Supply of Materials
There is currently only one UK supplier producing C Flute board that meets our standards. During late 2024 and early 2025, that supplier experienced significant supply issues, leaving us days away from running out of raw material for single wall boxes. By moving to B Flute—available from multiple suppliers—we ensure a consistent, uninterrupted supply for our customers.
3) Aligning with Industry Standards
Until recently, ASC Direct was the only online manufacturer offering C Flute for single wall boxes. Most manufacturers now use B Flute as standard. Aligning with this standard allows us to maintain faster lead times, better material availability, and consistent quality that meets or exceeds industry expectations.
4) Understanding the Difference Between B Flute and C Flute
| Feature | B Flute | C Flute |
|---|---|---|
| Thickness | ≈ 3 mm | ≈ 4 mm |
| Flutes per metre | Approx. 150–185 | Approx. 120–145 |
| Surface finish | Smoother, flatter—ideal for printing & branding | Slightly more textured |
| Stacking strength | Very good for most uses | Slightly higher for heavy-duty stacking |
| Cushioning | Moderate—general protection | Slightly more cushioning for fragile items |
| Common uses | E‑commerce boxes, postal cartons, shelf‑ready packs | Shipping boxes for heavier or bulkier items |
In practical terms, B Flute offers excellent strength‑to‑weight performance, while using slightly less material. It’s easier to print on and more space‑efficient in storage and transport. That’s why most packaging manufacturers—and their customers—use B Flute as standard.
5) What This Means for You
For around 98% of customers, the change from C Flute to B Flute has been virtually unnoticeable in everyday use (updated 1st October 2025) B Flute provides excellent performance for most packaging needs and strong protection for shipping and storage.
For heavier loads or longer boxes (over 550mm in length), we recommend our double wall cardboard.
Still want C Flute?
If you’re ordering in bulk (over 500 boxes of one type), we can special‑order C Flute. Please note: production and despatch times will be longer than using the Box Builder.
6) Keeping You Informed
We notified customers about this change by email on 7 May 2025, ensuring transparency and continuity of supply. Since then we have also updated the box builder and the reorder page.
Not sure which cardboard is right for your products? We’re happy to assess your use‑case and recommend the best fit. Call us on 0800 0731 126 (Monday to Friday 9am - 5pm)