3-ply, 5-ply or 7-ply: how to choose

Ply is the number of paper layers in the board. A 3-ply board has two liners and one fluted layer between them. A 5-ply has two fluted layers, and a 7-ply has three. More ply means more strength, more weight and more cost.

For most products, weight decides. Up to about 10 kg, a well-made 3-ply carton is enough. From 10 to 25 kg, choose 5-ply. Above 25 kg, or for anything fragile and heavy like ceramics or machine parts, use 7-ply.

Then think about stacking. A box at the bottom of a pallet carries everything above it, sometimes for weeks in a warehouse during the monsoon. Damp kraft loses up to half its strength. If your boxes are stacked high or stored in humid godowns, go one grade up or ask for a moisture-resistant liner.

Finally, the journey. Boxes that travel by road across states get dropped, squeezed and rained on. A box that only goes from your factory to a local distributor can be lighter. Tell us the route and we will suggest a spec, then test a sample under load before you order.