Corrugated cardboard is board made from flat sheets of paper, called liners, with a wavy layer of paper, called the fluting, glued between them. Single wall board has one fluted layer between two liners, and double wall board has two fluted layers and three liners, so double wall is the thicker and stronger of the two.
This guide explains how the board is built, how single wall and double wall differ in plain terms, how to tell which one you are holding by looking at the cut edge, and how corrugated board differs from plain card. It then lists which of our boxes are sold as corrugated, with sizes and prices, and how to buy them.
In This Guide
- Quick picks for corrugated boxes
- What is corrugated cardboard?
- What is the difference between single wall and double wall corrugated board?
- How can you tell if a box is single wall or double wall?
- Is corrugated cardboard the same as cardboard or card?
- Which Pack Solution boxes are corrugated?
- When is single wall corrugated board enough?
- How do you buy corrugated boxes: quantities, cost per box and delivery?
- Frequently Asked Questions
Quick picks for corrugated boxes
These are the box ranges we stock, starting with the two that are listed by wall type.
Best for light, everyday parcels
Single Wall Cardboard Boxes
Lightweight corrugated boxes with one fluted layer, for online orders, storage and light moving.
- 15 sizes, 5 x 5 x 5" to 24 x 18 x 18"
- Sold per box, minimum 5 per size
- Supplied flat packed
From £0.35 ex VAT (£0.42 inc VAT)
Choose sizeView product
Best for heavy or fragile goods
Double Wall Cardboard Boxes
Heavy duty corrugated boxes with two layers of fluting, which stack better than single wall.
- 11 sizes, 9 x 6 x 6" to 24 x 24 x 24"
- Sold per box, minimum 5 for most sizes
- Supplied flat packed
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView product
Best for fast packing
Crash Lock Boxes
Cardboard boxes with a base that locks itself as you open the box, so there is no tape underneath.
- 10 sizes, CL-A (100 x 100 x 70mm) to CL-K (426 x 300 x 300mm)
- Sold per box, minimum 5 per size
- Only the top needs closing
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView productWhat is corrugated cardboard?
Corrugated cardboard is a sandwich of paper: two flat outer sheets with a wavy sheet glued between them. The flat sheets are the liners and the wavy sheet is the fluting, sometimes called the flute or the corrugated medium.
The waves make the board useful for packing. They hold the two liners apart, so the board is much thicker than the paper that went into it, and they run in rows like small arches. That shape resists bending along the length of the flutes and gives a little under a knock, which is why most shipping cartons and moving boxes are made from corrugated board.
- Liner: the flat paper you see on the outside and the inside of the box.
- Fluting: the wavy paper glued between the liners. You only see it at a cut edge.
- Wall: one fluted layer with a liner on each side. Board is named by how many of these it has.
What is the difference between single wall and double wall corrugated board?
Single wall board has one fluted layer and double wall corrugated board has two. Count the papers and single wall is three layers (liner, fluting, liner), while double wall is five (liner, fluting, liner, fluting, liner).
| Single wall | Double wall | |
|---|---|---|
| Fluted layers | One | Two |
| Flat liners | Two | Three |
| Thickness and weight | Thinner and lighter | Thicker and heavier |
| Strength | Keeps its shape in the post with light contents | Stronger, and stacks better |
| Our range | 15 sizes, from £0.35 ex VAT (£0.42 inc VAT) a box | 11 sizes, from £0.59 ex VAT (£0.71 inc VAT) a box |
The second fluted layer makes the side of the box stiffer, so a stack is less likely to buckle, and puts more material between the contents and whatever hits the parcel. It also makes the box heavier and more expensive. For a light item that is not fragile, single wall does the job.
If you are deciding between the two for a particular product, our guide to single wall vs double wall cardboard boxes goes through that choice in detail.
How can you tell if a box is single wall or double wall?
Look at a cut edge of the box and count the rows of waves: one row means single wall and two rows mean double wall. The top edge of any flap shows it, and you do not need to cut or damage the box.
- Open the box, or pick up a flat one, and find a raw cut edge. The end of a top flap is the easiest place.
- Hold the edge up to the light and look at it end on, so you are looking down the little tunnels the fluting makes.
- Count the rows of waves. One row between two flat liners is single wall.
- If you see two rows of waves, one above the other, with a flat liner running between them, the box is double wall. The two rows are often different heights.
- If you see no waves at all and the edge is one solid layer, the box is plain card and not corrugated.
Check the edge, not the face. A printed or smooth outer liner tells you nothing about what is inside the board. Two boxes that look the same from the front can be single wall and double wall.
Is corrugated cardboard the same as cardboard or card?
Corrugated cardboard is one kind of cardboard. "Cardboard" is a loose everyday word that covers any stiff paper based board, including corrugated board and plain solid card.
Plain card, which the trade often calls cartonboard or solid board, is a single dense sheet with no fluted layer. Cereal boxes, tissue boxes and greetings cards are made from it. It folds neatly and prints well, but it is thin and has no air gap, so it gives much less cushioning than corrugated board.
So a listing that says "cardboard box" may or may not be corrugated. For a parcel going through a carrier network you want corrugated packaging boxes as the outer, and the cut edge test above tells you what you have.
Which Pack Solution boxes are corrugated?
Our single wall cardboard boxes and double wall cardboard boxes are both corrugated boxes, and they are the two ranges we list by wall type. All of our boxes are plain stock boxes. We do not sell custom printed boxes.
| Range | Board, as listed | Sizes | Price from |
|---|---|---|---|
| Single wall cardboard boxes | Single wall corrugated | 15 sizes, 5 x 5 x 5" (127 x 127 x 127mm) to 24 x 18 x 18" (610 x 457 x 457mm) | £0.35 ex VAT (£0.42 inc VAT) a box |
| Double wall cardboard boxes | Double wall corrugated, two layers of fluting | 11 sizes, 9 x 6 x 6" (229 x 152 x 152mm) to 24 x 24 x 24" (610 x 610 x 610mm) | £0.59 ex VAT (£0.71 inc VAT) a box |
| Crash lock boxes | Cardboard, wall type not listed | 10 sizes, CL-A (100 x 100 x 70mm) to CL-K (426 x 300 x 300mm) | £0.59 ex VAT (£0.71 inc VAT) a box |
| Royal Mail PIP large letter boxes | Die cut cardboard, wall type not listed | Mini, C6, DL, C5 and C4, all 20mm deep | £5.00 ex VAT (£6.00 inc VAT) a pack of 50 |
Two layers of fluting
Double Wall Cardboard Boxes
The range to look at when the contents are heavy, breakable or going to be stacked.
- 9 x 6 x 6" up to 24 x 24 x 24"
- 12 x 9 x 6" and 12 x 9 x 9" take an A4 sheet flat in the base
- Minimum 5 boxes, or 90 for the 24 x 24 x 24" size
From £0.59 ex VAT (£0.71 inc VAT)
Choose sizeView productCrash lock boxes and Royal Mail PIP large letter boxes are listed as cardboard boxes, and their product pages do not give a wall type. If the board matters for what you are sending, ring us on 0161 706 1246 or use the contact page and we will check the size you want. Once a box is in your hands, the cut edge tells you in a few seconds.
Those two ranges are chosen for their shape. Our guide to slotted boxes and other box styles explains how the styles differ, and the large letter boxes guide covers what fits in a 20mm deep PIP box.
When is single wall corrugated board enough?
Single wall corrugated board is enough for light items that would survive a short drop, such as clothing, books, boxed accessories and most everyday online orders. Our single wall range is described as light shipping boxes that keep their shape in the post, and it starts at £0.35 ex VAT (£0.42 inc VAT) a box.
Move up to double wall when the contents are heavy, breakable or valuable, or when the boxes will sit in a stack in a van, a warehouse or a storage unit. Double wall is also the usual pick for a house move, where boxes get lifted, stacked and carried several times.
The board is only part of the protection. A fragile item in a double wall box still needs wrapping and the gaps filled, which is what the bubble wrap and void fill range is for. A box that is the right size also matters more than an extra layer of fluting, so check the cardboard box sizes chart before you order. For a move, the moving boxes guide covers how many boxes you are likely to need.
How do you buy corrugated boxes: quantities, cost per box and delivery?
Our single wall, double wall and crash lock boxes are sold per box with a minimum of 5 per size, so you can try a size before you commit to a large order. The exception is the 24 x 24 x 24" double wall box, which has a minimum of 90. PIP large letter boxes come in packs of 50.
- Cost per box: single wall starts at £0.35 ex VAT (£0.42 inc VAT) and double wall at £0.59 ex VAT (£0.71 inc VAT). The price per box falls as the quantity rises, and each product page shows the tiers.
- Delivery: Royal Mail Tracked 48 is free on every order with no minimum, and orders placed by 2pm Monday to Friday leave our Manchester unit the same working day.
- Collection and local delivery: click and collect in Manchester is free and usually ready within 2 hours. We also run same-day van delivery within 10 miles of Cheetham Hill.
You will need tape as well, since a standard corrugated box is taped along the base and the top. Packing tape is sold in packs of 6. If you buy boxes every month, a trade account is worth setting up, and a VAT invoice comes with every order either way.
Frequently Asked Questions
What is corrugated cardboard made of?
Corrugated cardboard is made of paper. Flat sheets called liners are glued to either side of a wavy sheet called the fluting. Single wall corrugated cardboard has one fluted layer and double wall corrugated cardboard has two.
What does double wall corrugated mean?
Double wall corrugated means the board has two fluted layers and three flat liners, stacked liner, fluting, liner, fluting, liner. Double wall corrugated board is thicker and stronger than single wall board and stacks better. Pack Solution sells double wall boxes in 11 sizes from 9 x 6 x 6" to 24 x 24 x 24".
How do I know if my box is single wall or double wall?
Look at a cut edge of the box, such as the end of a top flap, and count the rows of waves. One row of waves between two flat liners means the box is single wall. Two rows of waves with a flat liner between them means the box is double wall.
Is corrugated cardboard stronger than normal cardboard?
Corrugated cardboard is thicker and gives more cushioning than plain card of the kind used for cereal boxes, because the fluted layer holds the liners apart. Plain card is a single solid sheet with no fluting. That is why shipping cartons and moving boxes are made from corrugated board.
Which Pack Solution boxes are corrugated?
Pack Solution single wall cardboard boxes and double wall cardboard boxes are both corrugated boxes. Single wall boxes come in 15 sizes from £0.35 ex VAT and double wall boxes in 11 sizes from £0.59 ex VAT. Crash lock boxes and Royal Mail PIP large letter boxes are listed as cardboard boxes without a stated wall type, so call 0161 706 1246 if you need the board confirmed.
