Single wall or double wall? Choosing the right cardboard box
What the difference is, when each makes sense, and how to avoid paying for strength you don’t need.
Corrugated cardboard is made from a wavy layer of paper (the “flute”) glued between flat sheets (the “liners”). Single wall board has one fluted layer; double wall has two, with an extra liner in between. That second layer is what makes double wall boxes stronger and stiffer.
When single wall is the right choice
- Lighter items — clothing, books, homeware and most online orders.
- Parcels that travel on their own rather than at the bottom of a stack.
- When weight and space matter: single wall boxes are lighter and take up less room flat-packed.
When to step up to double wall
- Heavier contents, or anything with sharp corners that could puncture a thinner wall.
- Boxes that will be stacked on pallets or in storage for a long time.
- House and office moves, where boxes are handled many times.
- Fragile goods, where a stiffer box keeps its shape and protects the cushioning inside.
Size matters as much as strength
A box that is too big lets goods move and crush in transit, needs more void fill and can push you into a more expensive courier band. Aim for a snug fit with just enough room for protective packaging around the item.