How to choose the right export carton

What is an export carton?

An export carton is an outer corrugated box built to survive sea or air freight, stacking in a container and handling at the port. Exporters call it a master carton when it holds several inner cartons or polybagged units. An inner carton is a smaller box packed inside the master carton. A common example is an RSC master carton with shipping marks printed on two or four sides.

Step 1 — Choose the construction

Start with the box style. The RSC (Regular Slotted Container) is the standard, economical export carton — all flaps are the same length and meet in the middle — and it suits the great majority of bulk garment and consumer-goods shipments. Step up to a Full Overlap (FOL) when contents are heavy or need extra edge protection, since its overlapping flaps add stacking strength. Use a half-slotted carton for re-packing and inner cartons, or die-cut and telescoping styles for retail-facing presentation. Our corrugated boxes overview shows all eight constructions we run.

Step 2 — Match the board grade and flute

Next, pick the board. The board grade sets the paper weights and fibre, and the flute profile sets thickness and cushioning — B flute for standard master cartons, AB double-wall for heavy or high-stack loads, E or B for printed retail boxes. If you are unsure how the callouts work, our board grades and GSM guide decodes them. The goal is the lightest board that still passes your strength target, so you do not pay for material or freight weight you do not need.

Step 3 — Set the strength target

Strength is specified by test, not by weight. Decide whether your shipment is governed by stacking (use ECT) or rough handling and punctures (use bursting strength), then set a target from your contents weight, stack height, transit mode and route humidity. Long, humid sea voyages need a higher margin than a short air shipment. Our bursting strength vs ECT guide explains exactly how to choose and size that target.

Step 4 — Size the carton correctly

Work out internal and external dimensions separately. Internal dimensions come from the packed unit size and the count per box, plus a few millimetres of clearance so goods are not compressed. External dimensions are what then have to tile onto a pallet and cube out a container. A carton that protects the product but wastes space on the pallet quietly inflates freight cost on every shipment, so size for both at once. The free carton calculator gives you indicative board area and outer dimensions in seconds.

Step 5 — Plan print, marks and finishing

Decide what goes on the box: buyer artwork, shipping marks, carton numbering, barcodes and handling symbols. Match the print method to the flute — flexo for shipping cartons, higher-resolution work for retail-facing boxes — and confirm whether the buyer requires specific mark placement or colours. Getting marks and barcodes right at spec stage avoids rejected cartons at the DC. We print, die-cut and finish in-house and supply pre-production samples for approval before the run.

Step 6 — Optimise pallet and container fit

Finally, confirm the carton works at the unit-load level. Check that the outer footprint tiles cleanly onto your pallet pattern, that the stack height is stable and within the buyer's limit, and that the pallets fill the container efficiently. Even a few wasted centimetres per carton multiply across a full container into real money. We optimise outer dimensions so cartons pallet-tile and cube out the container, then verify the finished boxes against your spec. When your numbers are ready, request a quotation and we will respond within 24 hours.