Corrugated board is built from flat paper layers called liners and a wavy paper layer called the medium. The medium’s arches are called flutes. Together, the layers form a board that can be converted into shipping and storage boxes.
What does “ply” usually mean?
In common box descriptions, the ply count refers to the number of paper layers in the board construction. The typical structures are:
| Common description | Typical board structure | A useful note |
|---|---|---|
| 3-ply | 2 liners + 1 fluted medium | Often called single-wall board |
| 5-ply | 3 liners + 2 fluted mediums | Often called double-wall board |
| 7-ply | 4 liners + 3 fluted mediums | Often called triple-wall board |
These are common descriptions. Ask the supplier to confirm the actual construction in the quotation so you and the box maker are discussing the same specification.
Does a higher ply count always mean the right box?
No single ply count is right for every product. A box choice depends on the packed item, inside dimensions, how the box will be handled, whether boxes will be stacked, and any space or weight limits during storage and delivery. The paper grades, flute combination, box style, and any inserts can also affect the finished package.
That is why a higher ply count should not be treated as a complete strength rating by itself. Share what you are packing and how it moves through your supply chain, then ask the supplier to confirm the proposed construction and any performance requirements.
What should you include in a quote request?
- The product and its packed weight, if known.
- Inside dimensions in length × width × height order, with units.
- How the package will be shipped, handled, and stacked.
- The order quantity, print requirements, and delivery city.
- Any sample or testing requirements you need to discuss.
The TheBoxMakers standard corrugated range lists 3-ply to 7-ply options. The appropriate option and final specification should be confirmed against your actual product and delivery needs.
Further reading
For a technical overview of liners, fluted medium, and common board structures, see the Fibre Box Association’s corrugated guide. Its explanation describes single-wall, double-wall, and triple-wall board as one, two, or three fluted mediums respectively, between liner layers.
This guide is general information to help you prepare an enquiry. Confirm the material specification and product suitability for your application before ordering.